Compiling UE4.23.1 from source is taking up 90GB+ and growing each time I compile!!

At the very least VS is going to make sure you have enough space for the project to be rebuilt before it starts. You wouldn’t want to find that out halfway through a very long build.

I’d suggest reading through all the recent VS2019 posts on the forum and getting that set up instead. It’s faster and probably does a better job with available space.