You can only set the plunge rate. Im not sure if the retract rate is the same as the plunge rate or fixed. I never checked it. To set the plunge rate select a tool then go to EDIT. You will see the plunge rate near the bottom of the screen. To set the retract height, Click on design, then the little gear icon and you will see the retract height Default is 0.394
Looks like for drilling it retracts at rapid. (G0)
For contour & pocket, it retracts at the plunge feedrate.
V-carve & Adv V-carve retract at the cut feedrate.
For me doing Contour with no offset the retract rate is similar to feed rate, slow. Much slower than plunge rate but I’m plunging fast because i’m just using a spring loaded diamond bit.
I’ve used the FOSS (free open source software) program GCodeClean to turn feed rate retracts into rapids with Carbide Create gcode. I have a pre-MCEtcher diamond drag bit that needs about 5mm of spring travel, and from minor diamond mount cracking paranoid use comparatively low plunge speeds. The slow plunges were bad enough, watching the feed rate retracts ooze upwards was agony (well, slightly exaggerated), GCodeClean fixed it. Probably best to try it on something unimportant first just in case