Screenshotted the Fred view instead of trusting it, and it showed two things.

The transport read **133 bpm on a 132.5 bpm kit**, because selecting a kit rounded its
tempo. Harmless in a display, not harmless here: the rack sets `rate = dur / (bars ×
barlen)`, so 133 stretches every loop in that kit by 0.4% and the mismatch goes straight
into the audio. Half-integer tempos are ordinary in this corpus. No rounding, and the
"match this kit" button now compares to 0.01 bpm so it stops offering a value it already
has.

And `fred_bighen_bass` listed three loops all labelled `bass`, two of them also both
"8 bars · 132.5 bpm" — the kit is named for the stem, so the stem name distinguishes
nothing. The manifest already knew `start_s`, so rows now carry `@2:14`: where in the
source track this loop was cut from, which is the thing you actually want when choosing
between two loops off one stem.