The dense video default engages transformer auto-quant, and on Blackwell the
auto ladder leads with fp8. On the Wan DiT the production per-row fp8 path
(torch._scaled_mm) renders every frame black (mean luma 0.0 at 512x320 and
704x480, LPIPS ~0.80 vs bf16): Wan's activation outliers exceed per-row fp8's
range, the same failure already denied for qwen-image. First-Block-Cache then
over-caches the degenerate activations (per-step collapses to ~10ms),
compounding it.
Add the Wan families (wan2.2-ti2v-5b, wan2.2-t2v-a14b, same WanTransformer3DModel)
to _FAMILY_SCHEME_DENY for fp8/mxfp8/nvfp4 so auto falls through to int8, which is
clean on Wan (per-token, outlier-robust), saves the same weight memory on the DiT,
and lets First-Block-Cache engage normally instead of over-caching. mxfp8/nvfp4 are
denied alongside fp8 conservatively so auto lands on the battle-tested int8; they
can be re-enabled per family once validated in-bar, like the nvfp4 auto-ladder TODO.
Validated on B200: the shipped video default now selects int8 for the Wan DiT and
renders clean frames (mean 172.6) at 15.6 GB resident (down from 24.2 GB dense),
with First-Block-Cache engaged. Adds two deny tests; 48/48 transformer-quant tests pass.
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