Let's just assume for the sake of argument that I accidentally copied a 50 GB file into a save game location that now fills up my hard drive and I can't delete it because Galaxy keeps bringing it back.

What's the workflow to deal with that? (IF there is a way to do it...)

(That was really just an example, I don't know whether Galaxy would even sync a 50 GB file...
But I do have some files I'd like to get rid of but that Galaxy keeps reviving...)

Disable sync for that game, delete the file, then reenable sync. That should technically work. I'd back up your save files all the same. Galaxy's cloud back up sucks horribly with no option to save or overwrite files currently present either in the cloud or locally on your system.

That is what needed. A method to manage saves on the cloud.

This doesn't sound like you've actually tried it. ;)

If Galaxy keeps the saves even while disabling syncing, it'll still revive the old files once I reenable syncing...
Oh well, I guess I'll just have to try and hope that the syncing works in a way that it never screws up and deletes something by itself. ;)

Are you removing the saves with the file manager, or via the game?

If I remember correctly, the recommended way is to use the game and remove the saves through there.

Those are additional files I created, the game can't remove them.

I ended up simply disabling syncing for that game.

I had to disable syncing for Galaxy's flagship game (The Witcher 3) because of save folder bloat. My save folder is over 3GB, and while that isn't huge, it's over the 1GB limit and causes the game to fail syncing every time. Since this is the case, and huge save folders are typical in huge games like this where the default manual save is "Save to an unused slot" It seems silly to not have a file manager system or at least file check and ask for direction on what to do with specific files when there is disparity between the local and cloud save. Janky as Steam's cloud save is, it at least asks what you want to do when files are different.

Cloud win election 20 billion votes to zero! More people than on planet vote for Cloud in Russia! All hail Cloud!

Glory to Cloud!