MapKey(&Throttle, APUON, DOWN+DX52);
MapKeyR(&Throttle, APUON, TEMPO(0, UP+DX52, 500));
Used like this you have a 500 ms delay from trigger release, until the virtual button is released. Use any timing you find suitable. This will prevent flicker from the twitchy trigger.
This also means that you have to have a 500 ms pause between trigger presses.