That's an excellent setup ZEP
I've seen that mod and have thought about making one of medium size. The reason I have not done so is because I'm kind of lazy, and that I have a pot that is a good size for the Anova and I use the stove to preheat the water to temperature so the initial setup is very quick. It is kind of simplistic, but I use foil on the setup to prevent water loss - like an inverted tent it keeps the water dripping into the pot, and I never need to replenish the water.
However, the problem with my rig is that the size of my cooks are limited, so your solution might work better than mine.
In your first photo, is that a metal collar that is glued into the top of the cooler? ... and if you don't mind, what cooler brand did you use?