Test ordered one-slot DFlash2 placements and preserve results

experiments/dflash2-medium-20260920/README.md

@@ -55,3 +55,32 @@ Target loaded; draft allocation of1079.61MiB onCUDA0 failed with CUDA malloc
 OOM. No benchmark inference executed. Supervisor restored original production;
 health/smoke/kernel checks passed. No performance or quality conclusion can be
 drawn. See results/ and restore-verification.json.
+
+## User-ordered one-slot follow-up
+
+The user authorized this order after the initial two-slot allocation failure:
+
+1. One slot, target80:20, draft on5080.
+2. One slot, target80:20, draft on3060, regardless of whether the first works.
+3. Only if step2 fails: one slot, target70:30, draft back on5080. Moving both
+   additional target layers and the draft onto3060 would compete for its memory;
+   this fallback instead makes space on5080 for the draft.
+
+Context remains160000 and other quick-probe settings are unchanged. These tests
+are temporary; production containers retain their original two-slot arguments.
+Case JSON now controls slot count and draft device (historical quick.json keeps
+its original two-slot meaning). Failed attempts include an explicit error field.
+
+An active production request postpones startup for up to180 seconds; no live
+request is deliberately interrupted. The existing drain check still protects
+requests racing with the transition. Each attempt has its own result directory;
+previous results and the frozen Qwen reference are never overwritten.
+
+## One-slot results
+
+Priority1 fails during draft graph initialization: output.weight resides onCUDA1
+but draft backends are restricted toCUDA0. Priority2 works; priority3 therefore
+not run. German37.79 tok/s, code75.51 tok/s, 4196-token prefill1437.56 tok/s,
+recall3/3. Allocation160000 is not full-context validation. Original two-slot
+production restored and checked after both cases. See
+../../docs/DFLASH2_ONE_SLOT_20260920.md for comparison caveats and quality findings.