This works on Windows as well-- edit the same file MenuSetup.tr in:
C:\Program Files\Wolfram Research\Mathematica\13.1\SystemFiles\FrontEnd\TextResources\Windows
You'll have to open Notepad as an administrator. I did the edit, but the first re-launch didn't change the menu. I discovered this is because I left a copy of the original file in the same folder. Apparently, the FrontEnd searches for the first file named MenuSetup. I removed the copy from the folder and it worked.
