Three-way QA-quality bench (quote / pointer / JSON) over an expanded
22-question set × 3 samples = 198 LLM calls. Findings landed in
docs/qa-modes-bench-2026-04-30.md with per-question breakdown and
roadmap. Aggregate at bench time:
quote 31S 20H 15U 0e strict-rate 47% 7.7s
claim_lattice_pointer 14S 34H 18U 0e strict-rate 21% 4.4s
claim_lattice (JSON) 26S 12H 9U 19e strict-rate 39%* 4.4s
The 19 JSON-mode "errors" turned out to be HTTP 502 from vLLM upstream,
not parse failures — clustered, all on the JSON-mode pass, plausibly
correlated with `guided_json` stressing the grammar engine.
Two improvements based on findings:
(1) OpenAICompatibleClient grew retry on transient 502/503/504 with
exponential backoff (0.5/1/2s, 3 attempts default). Network-layer
errors (ConnectError, ReadTimeout, RemoteProtocolError) get the
same retry. Smooths over the cluster without changing semantics:
persistent failures still raise, transient bursts no longer
dominate the error column. Helps all modes; JSON benefits most.
(2) Pointer-cap behavior changed from hard SCHEMA_INVALID to
trim-and-verify. When `[E2,...,E14]` over-cites a single claim,
keep first N pointers, verify normally, record
POINTER_OVERFLOW_TRIMMED in violations. STRICT becomes unreachable
(audit_mode caps at HYBRID) so the over-cite pattern stays
surfaced — but a correct claim like "Leonardo da Vinci painted
the Mona Lisa." no longer gets nuked for cosmetic over-citation.
Pre-fix: pointer mode hit 0/3 STRICT on Mona Lisa (mega-bracket
triggered SCHEMA_INVALID). Post-fix: HYBRID 2/14 with the right
answer rendered alongside both kept source spans. The dropped
pointers count toward n_quotes so the denominator surfaces the
over-cite to the auditor.
Bench scaffolding: ANSWER_MODES tuple now includes "claim_lattice"
(JSON), Makefile default sweeps all three. Question set expanded
from 8 to 22 covering narrow factoid, broad descriptive, entity
list, relationship, comparison, niche, adversarial, out-of-corpus.
460 tests pass. Connecticut output stays clean (HYBRID 4/7); JP-
dinosaurs pointer mode still UNGROUNDED via the bare-name guard
(model emits one-token entity names, the right floor catches them).