Hi Yek (really Yek this time LOL!)
With the same delay block, using the same delay algo, but with different regen, delay note durations (tempo sync'd with same tempo input), and different mix levels per channel, changing from the long delay/higher regen/50% mix channel, to the shorter delay/low regen/18% mix channel, effectively kills the long delay channel's tails.
Additional delay blocks would allow the long delay/hi regen delay to be bypassed/mute fx in etc, which would allow the tails to fade normally.
Thx...