Qwen3.8 27B-heretic-VL MLX bf16, single-run multimodal

User reports Qwen3.8 at 13.2 t/s on an M3 Ultra with 512GB unified memory. Setup is mlx-vlm 0.6.13 with the unquantized bf16 MLX VLM build, peak memory 55.8 GB. The figure comes from one 470-token image-plus-text prompt, one run per build, presented as an order-of-magnitude guide rather than repeated benchmarking.