Bottom line is measuring rotation speed is not rocket science. ANyone who is in question how well their table maintains proper speed should be able to measure and confirm as needed and put the issue to rest.
"How does one measure "rhythm and pace" again? That is totally subjective, which is fine if that works for you but has no real meaning or use to others accordingly.
I'd be willing to bet that practically imperfections in record manufacturing, warping over the years, etc. is a much bigger real issue than stylus drag with most any well designed and executed turntable. Of course, we have little control over that, so probably more practical to fret the details of stylus drag assuming those who created our SOTA turntables did not?
My records sound fantastic, so I see little value for me personally.