Yeah, that was a real lesson for me when I did LFS.
It was super neat when I got it running for a while, but young me that did it really didn't understand the concept of "Ok, but now you need to upgrade things". That was some of my first experiences with the pain of a glibc update and going "ohhh, that's why people don't run these sorts of systems".
I used versioned AppDirs for that, e. g. /Programs/Python/3.13/. If I don't need it anymore, the directory is removed and a script runs. Similar to GoboLinux. I do however had not use GoboLinux right now; GoboLinux unfortunately lacks documentation, LFS/BLFS has better documentation. Finding information these days is hard - google search has become sooooo bad ...
