After some time I have decided to revisit this build. As it turned out the designated power supply did not correct the squeal I was getting. Aparantly I just got lucky as the controls were just right to mask it during bypass. This discover set me back to having to unplug it unless I planned to use it.
Today I swapped the 3pdt for a 4pdt. I used the added pole to break the 9V supply during bypass. I worried that it might creat switch popping issues but it turned out to be just the thing. I'm pretty sure I mean it this time.
Also, I wasn't completely satisfied with the action of the envelope so I tried various LEDs without improved results. I eventually ran my SHO at full blast into it. It made a huge difference to have the extra push. It was like a whole new effect that I couldn't turn off. I plan to wire the boost into the circuit tomorrow for a permanent improvement. I haven't decided if I'm even going to put a trimmer on the SHO. I think I may just use a jumper to keep it at full tilt.
Give a man a match and he'll be warm for a day.
Set a man on fire and he'll be warm for the rest of his life.