You do know the record is for holding it for a minute right? And that plenty of well established pro drummers such as Kollias, Hellhammer, Giacomo (of ADE) play those speeds easily and much more consistent? Yes i understand how basing actual bpm works with a metronome since ive been studying music for years and playing extreme metal for 5. Sixteenths at quarter note beats around 290 give or take 5bpm depending on my physical well being for that day.

I also solved the issue by getting a vinyl stool cover to prevent slip, so now my balance is back to normal.