2 installed versions, separate settings

Trying to figure out how to maintain 2 completely separate versions installed on the same system. I have 2.3.x installed in a non-default directory because it has the CLI, and I have 2.6.4 installed in the default directory because it’s new and update-able. This somewhat works, but I run these with 2 different GPU’s selected sometimes at the same time and the settings changed in 1 version screw with the other one.

How do I get them to be completely independent of each other?

There’s no one that knows how the model settings are stored and applied? 2 versions installed in 2 different directories suggests that the model settings are stored in some global directory. Is there some workaround for this?