Envelope Sustain Modulation

I love the Echon 6 but have one feature request that I hope there is a way to implement at some point. Changing the envelope sustain parameter value while playing seems to me for many of my patches to be the most effective ways to give a sound life and change it’s character like a real instrument while playing. However, it’s not assignable as a modulation destination. I’m so bummed about this. I’m accessing it by sending cc25 while playing but I would really love the ability to assign a single cycle LFO, key velocity, or other sources to it in order to get it to respond to my playing as part of a patch and not by sending cc25 to it. Anyone have any thoughts? I realize this is probably a design choice and there may good reasons for not exposing it to modulation but I would sure love that as an add if it’s possible.