WS-E spine deferrals: known bugs and signed inconsistencies awaiting their increment

[juaristi22]

Parent: #145 (workstream E of the UK-migration epic #665). The spine-lane counterpart of #736 (WS-C calibration deferrals): a central checklist of every deferral, known bug, and signed inconsistency filed while the spine lane landed (#686 → #757 → PR #793), so nothing lives only in a PR body or an adjudication comment. Items graduate to their own issues when they become actionable; the committed signed-differences register (uk/spine_swap_signed_differences.json) remains the authoritative record of every intentional candidate-vs-incumbent deviation.

The capstone: the first certified cut

• Re-certify the candidate-of-record on a post-UK WAS stage: split private pension wealth out of corporate_wealth (#750) #755 spine. UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750 landed via UK WAS stage: split private pension wealth out of corporate_wealth (#750) #755 (2026-08-28), so spine-i no longer carries the UC lever the dispositions assume; spine-j (data/ukds/acceptance/spine-j-remeasure/, developer full build from main, gates green, private_pension_wealth present) needs the RC-strict battery + ladder + parity instruments + signed-differences re-mint before it can replace spine-i as candidate-of-record. Precedes the cut.

• Cut the first certified microcosm_uk_2024 line. The queue is down to 6 cells, all UC-side (v12, spine-j + the Revise the hmrc SPI band exclusions per the #807 support re-measurement #810 register revision: the 4 Band edges derive from the exclusion-pruned register, silently widening surviving banded targets #792 artifacts cleared with Fix #792: derive band edges from the compiled register, never the pruned roster #803, the sparse-band siblings cleared with the Re-measure the hmrc SPI band exclusions: three 'sparse cell' premises fail on spine-i (hundreds of in-band carriers) #807 lift, CGT slid inside the band): 2 TCL disability cells (UK spine: child disability under-identification blocks the TCL disability cells (−56.5% / −40.0% across three spine vintages) #808) + 3 composition cells and 1 payment band (UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809) — diagnosed as measurement-grain defects (see the 2026-08-28 capstone comments), re-bind PR designed. Also owed before the cut: the RC-strict battery + parity instruments + signed-differences re-mint on a post-UK WAS stage: split private pension wealth out of corporate_wealth (#750) #755 spine (spine-j is a developer build; spine-i's 14/14 battery does not transfer). Blocked-run receipts: data/ukds/acceptance/757-swap/ (13-cell era), runs/uk-623-first-calibrated/spine-assessment-v12/ (current). (2026-08-28 state: the queue is 8 cells on spine-j — the 4 Band edges derive from the exclusion-pruned register, silently widening surviving banded targets #792 artifacts cleared with Fix #792: derive band edges from the compiled register, never the pruned roster #803, and UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750, now landed and measured (+1.11m UC support, receipts runs/uk-623-first-calibrated/spine-assessment-v11/), moved UC caseload inside/near the bound; the 8 are dispositioned across Re-measure the hmrc SPI band exclusions: three 'sparse cell' premises fail on spine-i (hundreds of in-band carriers) #807 (sibling distortion), UK spine: child disability under-identification blocks the TCL disability cells (−56.5% / −40.0% across three spine vintages) #808 (2 TCL disability cells), UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809 (3–4 UC composition cells + the newly failing COUPLE_WITH_CHILDREN payment band), and obr.capital_gains_tax at exactly −25.0%, an adjudication candidate.)

• B4 completion / C4 (Swap the microcosm-built UK spine into the national build and retire the incumbent feed #757 items 9, 14): flip uk_input_mass_parity's reference to the just-cut line with run provenance, then retire the efrs-post-calibration descriptor and the incumbent filename pin (weighted_integrity.py, microcosm-data/contract.py). Cannot precede the cut (US Export input-mass-parity gate references the raw base, flagging correct calibration gains on PUF-imputed columns #327 doctrine). The frozen eFRS parity extraction stays as the historical instrument.

• W8 (Swap the microcosm-built UK spine into the national build and retire the incumbent feed #757 item 12): certified-identity registry entry for the cut artifact.

• UK scorecard: populace_uk_2023 vs enhanced_frs_2024_25 vs admin benchmarks (2026) #731 scorecard probe + rule-1 scorer seal: run against the certified line; the certification producer already cross-pins the score receipt.

• UK_REFERENCE_DATASET_NAME re-semantics once a second certified line exists — "reference" becomes the previous certified microcosm line (Swap the microcosm-built UK spine into the national build and retire the incumbent feed #757 item 13 note, terminal_gates.py).

• Retire the five obsolete release-fit deferrals: UC one-child, two-child, five-plus-child and lone-parent counts, plus the HMRC private-pension count £100k–£150k. Completed in Repair UC capital graph inputs and document calibration support gaps #892; all five remain in calibration and return to ordinary enforcement under the unchanged 25% bound. The evidence uses 1,500 updates / family_equal; this does not complete the certified cut.

Filed spine issues

• Derive NHS allocation (and audit age-conditioned imputations) from the disaggregated age surface #785 — derive NHS allocation (and audit age-conditioned imputations) from the disaggregated age surface; was blocked on the swap certifying, now unblocked by Swap the microcosm spine into the UK national build: self-policing build, retired June path, hardened parity instruments (#757) #787's merge

• UK spine: relationship-to-head frame column, so the ONS household-composition split is measurable #791 — relationship-to-head frame column so the ONS household-composition split is measurable; its three windowed exclusions expire 2026-11-26

• UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750 — split private_pension_wealth out of corporate_wealth (uk-data#452 M2): landed via UK WAS stage: split private pension wealth out of corporate_wealth (#750) #755 + policyengine-uk#1824 (2.92.0) + floors Floor the uk extra at policyengine-uk>=2.92 for the pension-wealth split (#750) #811; lever measured (UC support +1.11m, caseload −25.6% → −20.8%); residual owned by UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809/UK spine: child disability under-identification blocks the TCL disability cells (−56.5% / −40.0% across three spine vintages) #808 — landed via UK WAS stage: split private pension wealth out of corporate_wealth (#750) #755 and first measured 2026-08-28: UC initial support 3,128,938 → 4,242,978 with non-UC targets untouched; the residual is UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809

• UK CGT top-tail age and geography joints inherit from incidence and look off — benchmark against HMRC marginals #725 — CGT top-tail age and geography joints vs HMRC marginals

• Carry manifest rewrites into the shared Stage/StageRecord producer graph #721 — carry manifest rewrites into the shared Stage/StageRecord producer graph (in-place rewrites make stage-input state unreconstructible; E5's out-of-build refit instrument binds only pre-rebase)

• Tighten the UK input-mass tolerance by receipting the explained top drifts #713 — tighten the UK input-mass tolerance by receipting the explained top drifts (the gate note declares the re-mint procedure)

• Adjudicate the UK spine grain at the ingest/calibration seam #688 — the open half of the spine-grain adjudication (E10 gate arithmetic)

• Net-new UK stages: UC deduction attributes, bus fares, WAS debt #685 — net-new UK stages: UC deduction attributes, bus fares, WAS debt

• Legacy 2023-vintage build of the microcosm UK spine (deferred) #687 — legacy 2023-vintage spine build (deferred)

• policyengine-uk-data#469 — the incumbent's ETB per-head division (upstream defect of the UK: banded CGT gains targets (by size of gain) to constrain the distribution, not just count + total #467 family, observed during E10)

• Re-measure the hmrc SPI band exclusions: three 'sparse cell' premises fail on spine-i (hundreds of in-band carriers) #807 — re-measure the hmrc SPI band exclusions: three "sparse cell" premises fail on spine-i and spine-j (77–1,158 in-band carriers); lifting them re-couples the amount/count pairs (the +38.6% self_employment_income_count_50k_70k sibling distortion is the live symptom)

• UK spine: child disability under-identification blocks the TCL disability cells (−56.5% / −40.0% across three spine vintages) #808 — child disability under-identification on the FRS disability stage: the two TCL disability cells run −56.5% / −40.0%, invariant across spine-c/i/j; blocks 2 of the 8 capstone cells

• UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809 — the UC residual after the pension-wealth split (support 4.24m vs 6.76m): promote the wealth-block re-draw undershoot from UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750's follow-ups, re-measure the U8 would_claim_uc 0.55 freeze on its requested new evidence, and the composition shape (2-children fails while 1 and 3 fit); owns 3–4 of the 8 capstone cells

• UK spine: preserve FRS benefit-unit capital for UC while retaining WAS household wealth #828 — preserve FRS benefit-unit capital for UC while retaining WAS household wealth: carry TOTCAPB4 into uc_reported_capital, preserve the WAS wealth surface and top tail, make SPI UC/capital writes coherent, and refresh would_claim_uc after the final reported-UC write; no disagreement-conditioned twins.

• UK spine: condition SPI UC receipt on benefit-unit composition and add a UC-specific child count #832 — make SPI UC receipt coherent with benefit-unit composition and combined income, and add a UC-specific child count for the DWP numbered-child targets; successor to UK spine: preserve FRS benefit-unit capital for UC while retaining WAS household wealth #828 after its capital-coherence fix.

• Port post-freeze UK childcare/TFC spine inputs and calibration contract #834 — port the TFC work recently done in uk-data into microcosm.

• UK spine: composition-faithful SPI income draw — bridge predictors and rank-preserving replacement (with-children UC residual) #840 — improving SPI income imputation to preserve household characteristics like family structure or employment type

• UK FRS stages evaluate policy parameters at the survey period: declare a policy-year rule (uk-data#475, uk-data#478) #862 — FRS stages evaluate policy parameters at the survey period (uk-data#475 disability-threshold year and uk-data#478 DSA gate, inherited via parity; uk-data#476 reduces to the SPI-refresh week mix; uk-data#477 is covered by frs_release.json + test_uk_frs_release; uk-data#479 is an input to Adjudicate the incumbent's four post-calibration aggregate scalers #790; incumbent fix uk-data#480)

• UK spine: savings interest income a third under HMRC SPI and five times under the ONS D.41 row — reconcile the target concept and review FRS interest capture #866 — savings interest income: the spine carries £13.8bn at 2025 vs HMRC SPI £18.3bn (taxpayers, 2023-24) vs the ONS D.41 row £95.5bn; a frame gap plus a target-concept gap (measure exclusion ons.savings_interest_income, First calibrated rowwise UK local candidate (#495 increment 6) #762 A16, expires 2026-10-03)

• UK spine: housing benefit £2.7bn against OBR £12.1bn — pensioner and supported-accommodation HB missing after the UC migration #867 — housing benefit £2.7bn vs OBR £12.1bn: pensioner / supported-accommodation HB after the UC migration (exclusion obr.housing_benefit, A16, expires 2026-10-03)

• UK spine: SLC plan-2 borrower stocks at a third of SLC's — the FRS flag captures repayers, not the liable stock #868 — SLC plan-2 borrower stocks at a third of SLC's: the FRS flag captures repayers, not the liable stock (exclusions slc.borrowers.plan_2_liable, slc.borrowers.plan_2_above_threshold, A16, expire 2026-10-03)

• UK spine: JSA claimants 2.8× the DWP caseload — legacy-benefit reporting after the UC migration #869 — JSA claimants 2.8× the DWP caseload: legacy-benefit reporting after the UC migration (exclusion dwp.jsa_claimants, A16, expires 2026-10-03)

• UK bus fares: impute journeys from NTS microdata so the DfT receipts targets are not level-set by the stage (#890 follow-up) #930 — UK bus fares: impute journeys from the NTS microdata (UKDS SN 5340) priced at the published revenue per journey, so the DfT receipts targets bound in Bind the Chronicle transport and energy facts on the UK national surface (#890 PR-T) #904 are no longer level-set by the Bind DfT, HMRC, DESNZ, Ofgem and ORR facts for bus fares, road fuel, domestic energy and rail support (#790 ruling: bind facts and calibrate) #890 lcfs rake and incidence draw (María's ruling 2026-09-15 on UK #890 PR-S: uprate the LCFS and ETB donors, condition on vehicles, draw NTS bus use, rake bus and energy to vendored facts, price energy at the FY2024-25 cap #927; rake and target kept together as the interim, ONS 07.3.2 recorded as a diagnostic)

Deferrals and signed inconsistencies without their own issue yet

• UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750 residuals (graduated 2026-08-28 on closure): the composite mass audit (old corporate wealth vs corporate + pension, so the input-mass gate distinguishes the intended transfer from pension-mass loss); the cash-ISA gap (cash_isa is capital for the means tests but the model's savings maps savings accounts only); current_db_pension_wealth (£1,149bn current-employment DB not carried). The mirror→re-pin ordering stays on B4 above; the re-draw undershoot is UC residual after the pension-wealth split: support 4.24m vs 6.76m — re-draw undershoot, the 0.55 take-up freeze, and composition shape #809 M1 + Port UK compact source stages and 2024-25 refresh from uk-data #145.
• macro_realism for the UK (Swap the microcosm-built UK spine into the national build and retire the incumbent feed #757 item 9): named in the arming item but never declared — no uk/gates.json entry and no UK_GATE_REGISTRY binding exist (only the Belgium precedent). Decide arm-or-drop; arming needs a UK metric/band source plus a new binding.
• Household-surface QRF tail gate: the 12 household_qrf_tail grids (was_wealth surface) are measured in the Assemble the microcosm-built UK spine: whole-spine parity and swap acceptance #686 L3 baselines but not armed — uk_qrf_tail_concentration covers the 47-column HMRC person surface only (deferred in PR Complete the #757 deferrals: the exclusion pass, the measured U8 lever, the release-cut certification, and the re-armed thresholds #793; needs a household-surface evidence function and gate entry).
• uk_take_up_signal semantics: the gate sits terminal, so it compares weighted post-calibration shares against unweighted contract targets — not the same statistic pre/post calibration. Flagged during Swap the microcosm spine into the UK national build: self-policing build, retired June path, hardened parity instruments (#757) #787; unruled.
• owned_land seed instability (its reviewed input-mass exclusion expires 2026-09-26): the winsorised-donor / separate-land-imputation revisit registered on Port UK compact source stages and 2024-25 refresh from uk-data #145 (comment 5341180811); the reviewed input-mass exclusion was re-signed 2026-08-26 on a fresh 25-stage stability receipt (swing persists at 53.8% national) and expires 2026-09-26 — re-sign on fresh evidence or fix before then.
• E8 mass-change reasons: five pre-E8 stage families still declare the generic fallback reason instead of a stage-named one (standing follow-up from the Port the CGT structure, salary sacrifice, and student loan stages onto the UK spine at FRS 2024-25 #740 adversarial round 2).
• E7 reviewed-absent incapacity: hmrc_spi_incapacity_benefit_income is reviewed-absent per the Create the SPI income channel on the microcosm spine with the FRS-only second stage #683 adjudication; the stage fence (not the gate) promotes it when a future FRS vintage carries signal. Standing, self-enforcing — listed so the convention is findable.
• communication_consumption register scope: the one LCFS column where the incumbent is closer on level while the candidate is closer on share; signed inside the donor-faithful class, with a one-line rescope on offer if the adjudicator objects (Assemble the microcosm-built UK spine: whole-spine parity and swap acceptance #686 ledger, still open).
• student_loan_balance direction: signed on the register with the direction unevidenced beyond the E5 donor-truth measurement (Assemble the microcosm-built UK spine: whole-spine parity and swap acceptance #686 ledger, still open).
• UK parity increment 4: port the weighted integrity gates (input-mass parity + QRF tail concentration) into the UK terminal battery (#578) #609 disclosure confirmation for the published parity numbers (carried from the Assemble the microcosm-built UK spine: whole-spine parity and swap acceptance #686 queue).
• T4 lead — LCWRA element caseload (both artifacts ~3x the anchor): the T6-era admin battery (first run 2026-08-30, receipts uk-candidate-eval/out/v15/t4_admin.json) measures UC LCWRA-entitled at 7.42m (candidate) and 6.48m (incumbent) against the DWP Stat-Xplore anchor of 2.42m (LCWRA-Higher entitlement, Apr-Dec 2025 mean, chronicle#187/Assign US congressional districts from Ledger facts #188). Both sides are wildly over, so adjudicate the probe's semantics (entitlement flag vs the paid element) before treating it as a spine defect — but the candidate runs 0.94m above the incumbent either way.
• T4 lead — multi-benunit household formation (candidate 2.3x the incumbent): the multi-family-household differentiator reads 6.57m (candidate) vs 2.84m (incumbent) vs the ONS Families and Households anchor of 244k. The anchor semantics need adjudication (the probe counts multi-benunit households; ONS counts multi-family), yet the candidate-incumbent gap is anchor-independent: the spine forms far more multi-benunit households than the incumbent, and the candidate lost all 4 T4 differentiators. Household/benunit formation shape is a spine question.
• T4 lead — income-tax mass shortfall: income_tax_total measures GBP 280.6bn (candidate) vs GBP 293.3bn (incumbent) against OBR EFO March 2026 Table 3.4's GBP 331.4bn — the candidate sits 3.8pp further under than the incumbent (-15.3% vs -11.5%) despite winning the SPI band surface 110-24 on the frozen register. The mass sits somewhere the banded targets do not bind; candidates: top-tail amounts, non-SPI channels, the calendar-average convention.
• Local-area support floor — the two micro-authorities (First calibrated rowwise UK local candidate (#495 increment 6) #762 A4 / A14, 2026-09-02): Isles of Scilly (E06000053) and City of London (E09000001) cannot reach the 50-row / ESS-50 / 50-source floor by clone count (7 and 14 positive-weight rows at K=4; 17 and 49 at K=10 on spine-m); reviewed exclusions in uk/local_area_support_exclusions.json, expiring 2026-12-02, re-measured on every candidate (a passing area retires the entry); their own local-authority cells are signed-deferred (local_authority_support_floor_excluded, 43 cells). Spine-side because the fix is frame rows for those areas, not targets. No issue yet.
• Council-tax band H spine support (First calibrated rowwise UK local candidate (#495 increment 6) #762 A14, 2026-09-02; re-measured on microcosm#934, 2026-09-15): spine-r carries the same 49 raw FRS band-H households, so the 296 English authority band-H cells stay signed-deferred (council_tax_band_h_spine_support_absent, no expiry) and Shetland's band-H cell joined them (no band-H clone at K=15). The 53 Welsh and Scottish band-H cells that do bind carry the family's three largest misses (Merthyr Tydfil and Na h-Eileanan Siar with targets of 2 and 5 dwellings, Stirling −43 %). Spine-side: more band-H donors or a band-H-aware draw retire it. No issue yet.
• Council-tax band support beyond band H — per-clone band redraw (microcosm#929 CT-B, graduated 2026-09-16 on closure): council_tax_band is the raw FRS ctband copied verbatim to all 15 clones, so an authority's band distribution can only be approached by reweighting rows that carry some other authority's band. After the taxbase re-base (microcosm#934) the family fits 99.6 % of its 2,511 authority cells within 10 %, and the residue is the band column: Na h-Eileanan Siar band A (−31 %), Derbyshire Dales band G (−38 %, the same cell on the VOA basis) and the three band-H micro-cells above. The route is a per-clone, rank-preserving redraw of council_tax_band from the assigned authority's taxbase band distribution (the assign_brma_by_cell + stable_identity_uniforms pattern), with council_tax re-imputed per clone; it is also the only route to lifting the band-H deferral at K=15. Spine-side. No issue yet.
• Per-block engine resolution mis-measures population-normalised formulas (First calibrated rowwise UK local candidate (#495 increment 6) #762 R15, 2026-09-03): --engine-blocks K in the rowwise candidate driver multiplies corporate_land_value (and land_value) by K because policyengine-uk allocates a fixed national aggregate by share of the block's total weighted corporate wealth; the release posture is single-block and the manifest now names the affected measures, but the driver flag still exists for constrained machines. Tooling-side, recorded here because it produced two false spine "defects". No issue yet.
• Cross-lane markdown sweep (Swap the microcosm-built UK spine into the national build and retire the incumbent feed #757 item 16 remainder): COVERAGE_PROGRESS.md, PROGRESS_BUILD*.md, _698-*.md, _*LANE-NOTES.md, FINAL_REPORT.md — historicize or delete in their own PR; the UK-lane markdowns were dispositioned in Swap the microcosm spine into the UK national build: self-policing build, retired June path, hardened parity instruments (#757) #787.

Standing records (not action items)

• The U8 would_claim_uc lever is measured and re-frozen at 0.55: the raise moves claimants off legacy benefits (housing benefit −0.0% → −52.4%) while leaving every UC cell unchanged; the contract entry carries the receipts. Do not re-raise without new evidence — the lever's disposition is UK WAS stage: split private pension wealth out of corporate_wealth (uk-data#452 M2) #750.
• The spine signed-differences register (14 entries incl. the quantitative bounds re-minted per candidate) is the swap-decision record; per-stage battery gates are the standing health checks.

Refs: #686, #757, PR #793, #736 (calibration counterpart), #665.

[juaristi22]

Capstone-state update from today's remeasure (evidence: runs/uk-623-first-calibrated/spine-assessment-{v10,v11}/):

The blocked-cell queue is now 8, not 13, and its composition changed. The 4 #792 artifacts are gone (#803's band-edge fix), and #750 — landed via #755 and measured for the first time today — moved UC support 3,128,938 → 4,242,978 (+1.11m benefit units) with clean isolation (non-UC initials byte-identical). v11's failing set: 3 UC composition cells (#809), 2 TCL disability cells (#808), 1 newly-failing COUPLE_WITH_CHILDREN payment band (#809), 1 sparse-band sibling distortion (#807 — the excluded amount sibling pushes the surviving count to +38.6%), and obr.capital_gains_tax at exactly −25.0% (forecast-vintage gap; adjudication candidate).

A post-#755 spine exists but is not the candidate-of-record: spine-j (data/ukds/acceptance/spine-j-remeasure/, gates green, private_pension_wealth present) was built today from main as a developer full build — spine-i's 14/14 RC battery, ladder, and signed_parity do not transfer. The cut now needs the RC-strict battery + parity instruments + signed-differences re-mint run on a post-#755 spine; suggest adding that as an explicit checklist item above the capstone, since spine-i no longer carries the UC lever the dispositions assume.

New issues to absorb into the "Filed spine issues" list: #807 (three "sparse cell" exclusion premises fail on both spine-i and spine-j — 77–1,158 in-band carriers; lifting them likely clears the +38.6% sibling), #808 (child disability under-identification, the two deepest cells, invariant across three spine vintages), #809 (the UC residual: re-draw undershoot promotion, the 0.55 take-up freeze's requested new evidence, composition shape).

Minor observation for the calibration counterpart (#736): VAT drifts +10.3% (v9) → +17.5% (v10) → +19.0% (v11) across register/exclusion changes — not blocking, but trending.

[juaristi22]

Capstone-state update — the #807 revision is landed and measured (v12: spine-j, the revised 44-entry register via #810, 364 targets bound; receipts runs/uk-623-first-calibrated/spine-assessment-v12/):

The blocked-cell queue is now 6, all UC-side. The three lifted class-B cells fit (+22.2% / +18.5% / +23.3%), the sparse-band sibling distortion resolved at the source (+38.6% → +0.1%), and obr.capital_gains_tax slid inside the band (−25.01% → −24.9%) — the hmrc SPI band surface is fully green for the first time. Remaining: the two TCL disability cells (#808: −56.5% / −40.2%) and the four #809 cells (composition −36.9% / −28.8% / −26.5%, COUPLE_WITH_CHILDREN payment band −46.4%).

Closures: #807 closed via #810 (revision validated). #750 closes via #811 (engine floor policyengine-uk>=2.92, lock → 2.92.1 — the last microcosm-side checklist item; certification readout on the issue). #792's data claim verified on the issue (the four artifact cells pass at published widths: +128.2% → +0.0% etc.).

#750 residuals graduating to this ledger (from the post-merge checklist): the composite mass audit (old corporate wealth vs corporate + pension, so the input-mass gate distinguishes the intended transfer from pension-mass loss); the cash-ISA gap (capital for the means tests, but the model's savings maps savings accounts only); current_db_pension_wealth (£1,149bn current-employment DB not carried). The uk-data mirror → efrs-post-calibration re-pin ordering stays on the existing B4 bullet; the wealth re-draw undershoot is owned by #809 (mechanism 1) with #145.

Diagnosis of the remaining 6 (exploration receipts on file, plan approved): the two #808 cells and the three #809 composition cells are measurement-grain defects, not spine gaps — the disability children cells sum the affected-children flag against a published all-children concept (sheet 04B counts every child: sibling rows prove exactly 3.00/4.00 children/household), and the composition cells are household-grain measures of DWP's benefit-unit concept (household-summed is_child counts other benunits' children; households_single_no_children is the union of two #791-excluded ONS cells minus their disambiguating predicates — same defect class as #791, but the fix is re-binding to the natively-carried FRS benunit grain, not the relationship-to-head column). The re-bind PR is designed and held pending go-ahead; the COUPLE_WITH_CHILDREN payment band is genuinely benunit-grain and needs the uk-data#452 adjudication or the take-up/composition work (#809 M2).

[juaristi22]

For the record (Vahid's ask on microcosm#967 and #937/#939): on 2026-09-18 I signed the one live deferral on the target-fit register, hmrc/self_employment_income_income_band_20_000_to_30_000@2025 (adjudication microcosm#796, approved 2026-09-18, expiring 2026-10-16). The 638-target v20 surface after the #906 region fan-out and #939 CGT bands pushes this national SPI band 0.34pp past the fence while spine-s itself improved the cell; the deferral is windowed to four weeks and the register entry points here.