I use LFO with a custom Envelop for filters and some effects but the LFO/Envelope always loops you can set it top only play once (one shot) it would be fantastic to have release on there basically an ADSR
See serums LFO for ideas 
+1
Yes, that would indeed be very much appreciated, as it would solve a lot of issues with combined attack and release settings for layered drums.
I once tried to create an Attack/Release doofer by using the gate, but I ran into some issues. So a native solution would be great!