Thank you for this. I'll do it as you saidgraybelt wrote: yes, ENV is the second tab in 3xosc
between the default oscillators and the arpeggio/octaves stack tab
there is the ENVelope for volume, cutoff, and resonance
for volume, the last parameter is RELease
which can ease cpu if reduced to or near 0.
also as musicbear said you might have to be modest with stacking up lot of effects
3xosc and other simple generators with some effects should be okay.
back in the days my pc couldnt bear even a few simultaneous instances of ZynAddSFx