- `[2026-07-14]` **NVFP4 spike: built the full MTP serve scaffolding BEFORE validating a plain NVFP4 serve was coherent.** Chased 6 sequential serve-config fixes (entrypoint doubled `serve`, arch `ForCausalLM`→`ConditionalGeneration`, `--language-model-only`, mamba-cache/`max-num-seqs`) across a **2.5hr GPU window** (quoted 30-60 min) — only to find the served model gibbers (`!!!!`). LESSON: smoke a PLAIN `/v1/completions` coherence check on the SIMPLEST config (native arch, no MTP, no splice) FIRST — validate the tracer bullet before building spec-decode scaffolding. Also cost an unnecessary re-quant (the `re:mtp.*` ignore fix that turned out moot). Diagnostic ladder in Current state.