We are casual server so... Why even limit to 100? There's 240+ hz displays now. Let the player decide but make the default setting 60 or 50. That is if the traction advantage isn't too big which is what people saying, although I'm not sure if that's the case. Was there a test of some kind?
Btw to get refresh rate that isn't 60 hz in fullscreen mode you can use an ancient program called RefreshLock.
Edit: ah, 100 is maximum MTA allows. Then 100 it is. Maybe they have a good reason to limit it to this number.