I am completely blown away by the IQ of the GW690. (I have the iii, but same lens). Just insane detail even wide open. Rivals my A7ii.
I process E-6 in my apartment. Film Photography Project or Freestyle Photo carry the "Arista Rapid E-6 Kit". $30 develops 8-10 rolls. So easy, especially if you already do B/W. Just 3 different solutions (2 Developer, 1 Blix).
Honestly, the hardest part is the initial mixing of the 3 solutions because it has to be done at @110º F. But that takes all of 10 minutes.
When you want to develop a few rolls, drop the 3 containers in the sink with hot tap water to get the liquid up to around 100ºF. I don't sweat the temps TOO much. As long as it's close. You can work at lower temps, but then it takes quite a bit longer to develop.
At 100ºF it's 6.5 min Developer 1, rinse 7 times, 5.5 min Developer 2, rinse, then 6.5 min Blix, rinse 5 min and hang. @25 min. It's amazing to see chromes come out of the tank...