love the stereo polyphase….really the env mode.
it’s a beautiful filter that doesn’t eat away too much tone
The EHX start-end controls with a sens (gain on the PP) control is a knockout. I like that you can set the limits of the musical range THEN set the sens for how it’s going to behave within that

* SUGGESTION : add the attack/decay controls from the Enigma style E(I assume it’s a similar topology)

of course,

*modernizing the power supply
and
*shrinking the dimensions would make it far more marketable

Personally, I’d say dump the LFO and make a killer envelope phaser