Processing one of my tom loops from Colliding Worlds for Groove Agent 4 (running in tempo-synced stretch-mode) with a multi-envelope controlled HP filter (and other things) in UVI Falcon, the envelope sequence was extracted from the same drum-loop. Basically this new function is a workaround for the missing audio input in Falcon where one could use the side-chain signal to trigger a follower which would modulate things.