I bagged both Envies and Proxies before. I really think the Envy is objectively the best driving putter on the market. It is a cheater disc. Has a true 0 HSS while still having a pretty typical fade for a stable putter. It's just bonkers how easy it is to throw. Proxy is in the same boat. Thrown clean it is pretty close to 0 turn also (I'd put its HSS similar to an Emac Truth, for reference), but then just elevators straight down with almost no fade. Proxy can hold a turnover if you really force it over but that is certainly not what it wants to do naturally if thrown flat.
As for filling the gap between Zone and Lucid-X Judge, the Envy is exactly that disc. Proxy would overlap too much with the LX Judge. They are definitely different discs (Proxy is faster, about 15' longer, with less fade but also better HSS compared to LX Judge), but the net result is pretty similar.
I pulled both Envies and Proxies out of the bag in late 2019, mostly to try minimizing molds. Proxy I could live without. The straight flyer is nice, but in low wind I'd rather hyzerflip a worked in Prime Judge and in windy conditions I'm probably not fully trusting the Proxy anyway. Envy though? I just never could cover those lines adequately with either a beat JB Zone or a LX Judge. I've had it back in the bag for a couple months now and it has been a birdie machine for driving on short Par 3s
I feel ya. I bagged Envies for a grip. I have a couple aces on the one P Envy I still have. Great mold, but hard to bag it alone since it is a little OS. I have a complex where I like similar feeling discs per the slot (mid, putter, etc.). So I'd feel weird bagging a beadless (well, kinda) Envy and Judge for throwing... shrugs... OCD that way.
At this point any popular mold is hard as heck to find anywhere anyway... might just stick with the judge or Reko for the time being!