GH Python3 'site-envs' life-cycle behavior?


I am starting to dip a toe into the new RH-8 Python3 components in Grasshopper. I wonder if there is some documentation regarding how the interpreter will behave that I might refer to as I try and understand this new system? Specifically, I am wondering about the use of the site-env folders for dependencies?

I understand that when the user creates a new PY3 script and add the # r: ... to it, GH will install packages via PyPi, which is great and seems to work well. And from my tests, I understand that these dependencies are installed in temporary (?) directories within .rhinocode/py39-rh8/site-env (yes?). Just from noodling around, it appears that there are separate directories which are created for Grasshopper script components vs. native Rhino python scripts, yes?

So my question is: how should we expect these directories to behave over time? Meaning - they appear to be temporary (random string name?) but are they? Will they be removed / cleaned out at some point in the application life-cycle? Do they get updated or removed periodically? Or should we expect that once created the first time, they will remain on the user’s install with the same name/location? Will there ever be more than one GH and one RH directory created?