model card: verification

README.md

@@ -35,6 +35,9 @@ Held to upstream's Python with `shifts=0` (random shifts make upstream itself no
 - One training segment through Core AI on the GPU: 136–147 dB PSNR against upstream's output.
 - Every one of 63 chunks of a 6-minute mix: worst stem 110 dB.
 - Whole clips end to end (10 s and 6 min): 127–148 dB on every stem.
+- One measured wrinkle in the runtime, not the model: the GPU returned a slightly wrong segment
+  about 2% of the time (77–105 dB), never the same one twice. A correct run is bit-for-bit
+  repeatable, so the host runs every segment twice and settles a mismatch with a third run.
 
 ## Use