is this garbage necessary?

Decide if you are having a heater.
If you are you just need to switch off/on a vacuum signal to run this valve.
My 71 Swinger had this, and it takes a lot of
load off the AC.
If you keep this feature active, you do keep the heat load out of the interior in the summer.
Unless you need defogging.........
A manual operated vacuum switch to that valve would allow you to decide when you want heater core flow.
Or replace it with a manual pipe shutoff, I did that on the 65 Dart GT.
With that, I could always let it leak a tiny amount all summer for defog.