I was quite surprise that there's no "Hold" control on envelope on drumrack/simpler ! I thought Ableton was done by musicians
When I have to play "one shot samples" (like drums), 95% of time I don't care about sustain/release, but attack, hold and decay when it's triggered. Of course there're many other situation where ADSR can be usefull, so, from my PoV, AHDSR is a good choice ...
Not a big programming challenge !
NB : an extended view of the sample windows (EQ8 style) and a view of envelopes, for coarse / fast adjustment (and even the final processed sample) can be a good stuff !