Refresh or rescan library folders without moving them?

[Cametokur]

About 3 months ago I backed up my entire library which was close to 3TB in anticipation of getting some better/bigger drives. I moved the games I knew I would be playing to the new drives, but now, I would like to "refresh" all of my Steam Library Folders, so that I know every game is up to date.

I know that if I were to remove the folders in Settings>Downloads>Library Folders and re-add them it would (in theory) scan those folders, I guess? Problem with this is, when I tried it with one SSD folder, it only "saw" the games I had manually added the locations for- it left some games out, and I can't be certain whether or not if they were launched, they would be updated and installed.

I am not worried if there are conflicts per-game. I would just like to know if there's an option to have Steam "check" each library folder. It used to be about 3TB on close to 6 unique drives. Now, I've done the moving of each game itself to 2 SSD and 1 HDD. Steam still shows that all of those games are still "installed" even though the paths have changed.

If it isn't possible for a full-rescan of entire folders, is it possible to verify integrity of multiple games at once, rather than going through them one by one?

Thank you for any help. I hope I don't need to use a 3rd party add-on, but if there's something super-good out there I'm not entirely opposed to it. Cheers everyone!

Edit - forgot to mention that "repair library folder" is probably what I have to use, but this is a bummer because it seems to be going through every single game including ones I recently installed on the new drives.