{
  "ok": true,
  "value": -0.5,
  "grad_dtypes": {
    "q": "mlx.core.float32",
    "scale": "mlx.core.float32"
  },
  "grad_shapes": {
    "q": [
      2,
      2
    ],
    "scale": []
  },
  "note": "This proves MLX custom VJP can return float STE gradients for int8 arrays, but not that full LFM2 experts fit."
}