A very silly but useful hack I did to get the MS flight sim install down to about 40GB (normally ~270GB) before I gave up on windows was this.

Set up a nextcloud server on a raspberry pi.

Install the client on your windows machine.

Add your games install folder as a connection on the nextcloud client and enable VFS (virtual filesystem)

Once synced, right click the folder and select “free up space…”

This will basically delete the file data from your local machine and redownload it whenever windows tries to access a file.

Now launch your game and it’ll take a while to start as it has to redownload the files it actually needs to run, but it won’t bother getting it doesn’t have to.