- `[2026-07-15]` **vLLM `max-model-len` does NOT free GPU VRAM** — the KV cache POOL is sized by `gpu-memory-utilization`, not max-model-len. Lowering max-model-len only caps per-request context + drops max concurrency; the pool still fills the util budget. To actually free VRAM, lower `gpu-memory-utilization`. (Bit the char-rp-reasoning "drop KV to 150K" ask: the 150K applied but freed 0 VRAM until util dropped 0.39->0.38.)