Qwen3.8 125B (6B active) Flash-Next

User reports Qwen3.8-Flash-Next at 72 t/s decode on an RTX 4090 with Strata, using Unsloth's UD-IQ4_XS quant at 262K context. Setup is Strata with route tail skip disabled (STRATA_ROUTE_TAIL_SKIP=0) and RAM-budget mode; prompt speed was about 2,000 t/s at 36K and about 2,900 t/s at 136K. The default skip of 7 gave 93 t/s at both 36K and 136K but doubled KL against Q8_0 (0.053 to 0.115), so the user chose quality. Strata's calibrator moved --spec-min-p from 0.5 to 0.7 for about +4% and confirmed --pcie-frac 0.20; values at 0.55 or higher cost 20-40%.