I'll keep a sharper eye on when pictures "disappear" from the camera due to the folder name changing and see if I can find what's ultimately causing the problem.
So far, vid capture works fine.
captured 40s at q80, 50s at q85, 40s at q90, 60s at q95 and 40s at q99
Those just happen to be when I said "good enough" and stopped the capture.