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

User reports Qwen3.8-Flash-Next (125B-A6B MoE) at 20.65 t/s generation on an RTX 4070 12GB with 64GB DDR5-5600 and Gen4 NVMe on Linux. Setup is llama.cpp with AtomicChat's 4.27 bpw GGUF, n-gram SSD offloading, --fit-target 512, and an MTP variant (PR #28243 + compact shared-Q4_K_M head) with -ncmoe 45, yielding 77-96% acceptance. Prompt processing is 300-350 t/s. Baseline was 6 t/s; master branch reached 19.35 t/s. User notes MTP gives limited gains at low VRAM because layers must be freed for the MTP head.