I was thinking of the case where F360 is approximating non-circular curves (e.g. adaptive clearing strategies) using many very short straight line segments so there are a lot of rapid direction changes. Mach3 is supposed to smooth these, as I understand it. This kind of tool path is bad news if Mach3 is configured to "exact stop" mode but in constant velocity mode it's fine.

On reflection, though, probably not very relevant as you are using analogue servo controls which introduces a whole bunch of other variables. Good luck!