Hey
@edjusted! I was running into the same issue setting up my new M1 Mini on Big Sur (coming from High Sierra). I have a very large user folder, but wanted to use external storage for most of it, rather than paying Apple's SSD upgrade prices. I was frustrated that the old symbolic link approach I've been using for years didn't work.
This discussion on the Apple Support Communities helped me figure out a workaround. Basically, iCloud Drive creates new folders as it needs them to be for "Desktop and Documents" sync to work. If you disable iCloud Drive, the symlinks will persist. But if you want to use iCloud Drive but don't use that feature, you can temporarily disable iCloud Drive, create the symlink, lock the symlink, and reactivate iCloud Drive. The symlink will persist.
I imagine there are other ways to do this, but this worked for me. Note, in my case, I was making a symlink to the Documents folder on an external drive, but I think the process may work for your use case too, and have adjusted the steps accordingly. And as ever, be super careful in terminal, particularly with the
rm command. Anybody else following along, make a backup of your data first, and disconnect it from the computer when messing around with user accounts!
1) Log out of iCloud Drive (Settings ->Apple ID -> iCloud) on the user account you want to create the Documents symlink.
2) Create a second admin user account, if you haven't already.
3) Log out of the account in which you want to create the symlink, and log into the second admin account.
4) In Terminal, cd to the user account where you want to create the symlink:
cd /Users/yourusername
5) *Delete protected folder*. In Terminal:
sudo rm -rf /Desktop\ Folder
6) *Create symlink to source folder*. In Terminal:
sudo ln -s /Dropbox/Desktop\ Folder
7) *Lock the symlink. This will keep iCloud Drive from overwriting it when/if you reactivate it.*
sudo chflags -h uchg /Desktop\ Folder
8) Log out/restart. (I restarted because… why not?)
9) Log in to the account where you created the symlink. Confirm that the symlink is working as expected, and that it is in fact locked (locked icon in your user home directory, or Get Info on ~/Desktop and confirm that locked is checked).
10) Turn iCloud Drive back on. Check to see that the symlink hasn't been replaced with a new Desktop folder.
11) Restart to confirm that the symlink persists.
Hope this helps!