Can one work around it in this case somehow by using the envelopes of the main synth to control the delay, maybe by using an intermediate control that is controlled by the envelopes and is able to “reach” the delay?
Just brainstorming here, I didn’t try it yet, but basically the system “knows” the needed stuff already, so an envelope follower isn’t really needed as long as both the main synth and the delay are inside Falcon.
In case the main synth signal is external, it may be possible to do it like for instance in Bitwig Studio where you have an envelope follower as a factory device (“Audio MOD”) and can drive any plugin device parameter with it.
Cheers,
Tom