As documented in "File and Folders View",
|The "Remove Folder from Quick Recovery" command is available in folders below the top-level Quick Recovery Folders folder, and removes the folder from the list of Quick Recovery folders.
I've never tried it before, but it doesn't seem to work - at least not in the way that I tried it.
I created the folders: 'C:\QR Test', and 'C:\QR Test\Subfolder'
Set 'C:\QR Test' as a Quick Recovery folder in a new sandbox that I created.
Immediate Recovery is off.
Saved a sandboxed Notepad document to 'C:\QR Test'.
Saved a sandboxed Notepad document to the 'Subfolder', also.
In Control's "File and Folders View', expanded the list of "Quick Recovery Folders", right-clicked on 'Subfolder' and chose "Remove Folder From Quick Recovery".
After a window refresh, the folder 'Subfolder' and it's file were still listed under "Quick Recovery Folders".
A manual 'Quick Recovery' or a 'Delete Contents' still offers the 'Subfolder' and its file for Recovery - and the files are then recovered.