Validate Medium microbatch 256 with authorized lower reserve

experiments/medium-microbatch-20260920/README.md

@@ -33,3 +33,11 @@ Judge walltime, prompt/decode rates, VRAM and the three-needle recall together.
 only461MiB free on5080, below the512MiB guard. No256 inference was executed.
 Args differ only in --ubatch-size. Production512 restored and checked. See
 ../../docs/MEDIUM_MICROBATCH_20260920.md. Do not claim a256 speedup or quality result.
+
+## Explicitly authorized lower-reserve follow-up
+
+reserve448.json lowers only this256 case to448MiB loaded free-memory minimum.
+It passed all three short probes: +7.1% prefill, short decodes essentially tied.
+Recorded peak free memory443MiB; the guard is a startup threshold, not a reserved
+allocation or runtime minimum. No full160K/vision/concurrency qualification.
+Production512 restored. See reserve448-comparison.json and reserve448-restore.json.