Which AEP do you have specifically?
For a microswitch trigger where you want to keep semi-auto, you'll need something that can detect the gearbox cycling.
In that case, the only option is the Perun ETU++
You can hook that up with microswitches to detect the trigger, selector and cutoff lever so that'll give you full control over the gearbox.
You'll need to manually glue each microswitch in place and make your own data cable to plug in to the ETU++ but they give you the pin-out at the end of the manual.
It's not so hard in a CMG (MP7, Mac10 etc) but in the pistols, it gets really tight.
I've done it once before in a pistol and it's a bit of a nightmare, I'll not be doing it again any time soon ?
If you're not fussed about the microswitch trigger, a Perun simple MOSFET would be fine or an AB++ if you want programming options but not the hassle of installing the microswitches.