To get the proper feedrate, you need to tell mach3 the diameter or radius of the part. You need to enter it into a DRO on the Settings page. Mach3 uses this value to calculate the proper feedrate, depending on where the Z axis is.
Here's where it get's a little confusing.
Depending on which version of Mach3 you're using, the DRO may be labeled either "Rotation Diameter" or "Rotation Radius".
The reality is that what Mach3 is expecting is really neither. What you need to enter in the DRO is the distance from the center of rotation to Z=0.
I guess I'm not following: When you initially do the Wrapped Job Setup, you have determined the Cylinder Diameter and at the time you save to the Post Processor (shown in the pictures I posted above) it will popup a screen showing what is about to be saved as a "txt" file.
Loading the file into Mach 3, by the picture you can see it shows the Diameter of the material. By clicking in the green portion of the "Z", I will set a positive 1/2 the material thickness. I will center the mill on top of material and zero out the X, Y and A fields in the Mach program. (My machine is setup in millimeters.)
For curiosity, I went into the settings, to see what it looked like after loading the file, but I didn't have to anything. I also double checked the general setup configuration and A-axis motor setup to see how I originally set it up, which shows nothing checked concerning DRO. I determined how fast I wanted the A-axis to turn when I first installed the machine and the initial Mach 3 setup.