Perhaps someone can confirm or deny, but I believe 60 hits per second is the peak when running 60FPS mode.
I have tried to add Shadow's speed over 6000%, it seems easier than 4900%. I'm not sure my feeling is right or not.
If you have time, there is a thread on here somewhere that goes over max hits per second between all the different options.
I think that it would be just based off frame rate in the game, and this would also be pretty hard to test. But interesting idea.