I tap with the soft tap feature built into the drill routine .
We had to adjust the VFD values to get the RPM to match what the screen says , compared to a strobe light that is made to read actual RPM.
Then we experimented by tapping soft plastic and observing what it does . You can also set up a piece of metal strapping that has one edge ground like a knife edge . clamp this down and engage the tap flute , and tap in air. then you can see if it is feeding , dwelling and feeding up , while observing what the metal strip is doing . You will never get it to synch perfect on soft tap . I bought an ER 25 tap collet from Technics .
They have a spring loaded inner part that will pull out ( but will not compress in )
So as long as the feed (lead ?)is a bit faster , the collet will compensate for a mis match in feed .
I have tapped 1000's of 8-32 holes in alum with no problems . Just keep in mind that once you get an rpm /feed that works , don't go messing with a good thing by upping the rpm.