OptiQ mixed-precision MLX quant (data-driven KL-sensitivity 4/8-bit) of
unsloth/Qwen3.8-27B.
Notable measured property: on matched item sets at t0.6 this mixed-precision recipe produced
0/50 non-converging (runaway) items where the uniform 4-bit sibling produced 7/51 —
evidence that precision, not architecture, drives the runaway class in this family.
Recommended sampling: temperature 0.6, top_p 0.95, top_k 20, min_p 0.0,
presence_penalty 0.0, thinking ON (budget 81920). Campaign:
https://github.com/ivan-avramov/mlx_local_stack.
