I see your point. But i still don't see the "biochemistry" of it. What is the extra force overcoming?
I'm talking in terms of separating a lysate from cell debris btw.
I'm not biochemist, but it seems to me that it's a question of maximum force applied.
A larger example: if you spun ME in a centrifuge going very, very slowly, you could do it for a long, long time with no noticeable effects at all. However, if you were to do so at a very high speed, for a very short amount of time, I would likely die (or be severely discomfited).
My guess is that there is a minimum amount of force necessary to actually separate the stuff in question, irregardless of the time period involved.