In Mach 3, open Config, then the General Config box. Check "constant velocity" . In the lower right, there's a box CV Control.
I set CV Distance Tolerance at 100 units ...... I have no idea what a unit is.
I set Stop CV on angles over.... to 35.
Worked spiffy, although the bit caught corners on the raised lettering, but only on square corners. I think this will just require fine tuning.
When I get a chance, I'm going to make a new file, much smaller, to try different options on.
BTW, the smaller stepover added an hour to my time on the 2nd sample, but it's still one fifth the time of doing it in exact stop.