Ok, I am stuck thinking of using a Tapmatic type tapper on a cnc as that is all I ever used. The only Procunier I used was the "drill press" type on a knee mill. The Tapmatics reversed differently than the Procunier so that is why the info I am giving isn't quite right. When your head stops moving down while tapping your tap will stop moving down, that is not the case with a Tapmatic. It will keep tapping for another .15"ish. With a Tapmatic you must feed the tap at pretty close the same rate as it wants to go based on the spindle speed or else you will have nasty problems. With a Procunier you can feed slower without any issues, other than clutch wear as rklopp pointed out. If your tapping head spindle doesn't have a "cushion" in the spindle for feeding too fast then you will want to feed around 95-98% of the feed rate based on the pitch and spindle speed.
What speed you want to drive your tap depends on your tap. Cut vs form, what percentage of thread you are creating, and if/what coating it has will make a big difference. I am sorry if this is too detailed but I do larger part runs where saving or losing a second a hole matters. Your spindle speed for tapping will be between 1000rpm to as fast as your tapper will go.
Keep in mind that we are all giving general advice and when you start defining the details that advice will change. We learned most of this by trial and error. You are going to have to take all of our advice and keep it in mind when setting up and running your tapper.
I really liked these reversing tapping heads. When the company I worked for got a Fadal and we were tapping up to 80,000 holes a month with it that is when I fell in love with them. Tapping those holes using ridged tapping would have taken about 30 times longer and probably kill a few spindle drives, according to the tech who installed it. Watching that Fadal tap 4-40 holes about as fast as it could spot them at 3000 rpm through 1/8" aluminum plate was impressive.
Here is the
manual for your tapper. Whatever you do DON'T OIL IT TOO MUCH!