Qwen3.8 Heretic2

User benchmarks 12 quantizations of Qwen3.8-Flash-Next on an AMD Strix Halo 128GB, reporting 24 t/s decode and 312-382 t/s prefill at 512-2K tokens with llama-server. Setup is llama.cpp (llama-flash-next fork) with the Heretic2 IQ4_XS NGQ4 GGUF at 65,536 context, using Vulkan backend; the 92 GB model fits in 128 GB unified memory. Halogen Flash Server shows 2-4x faster prefill (453-1,203 t/s) but accuracy collapses to 65.2% without its proprietary overlay, and it forces thinking mode.