I did the Envy/Proxy pairing last year, and the problem I had was on approaches. They are the best driving putters available, but the same attributes that make them great driving putters also make them mediocre approach discs. I found them too fast and torque resistant to use for things like touch anny approaches around trees. I think if I were to try to fully rely on Evies/Proxies as my main putter molds again, I would likely only do so if I also carried something slow and lid-like for approaches.
I honestly really like approaching with my proxy. But I FH my zone quite a bit too and don't really use proxy or Envy on anny much. I could see your point there