For both main and non-main. I tried both.
At first I didn't even have the multi-user feature enabled under the Experimental Quest 2 settings menu, (it's off by default because it's still under Experimental settings).
I saw the other person's post here that "This issue appears on my Quest 2 only under the non-primary user."
So I tried enabling the multi-user feature and creating another account (one primary, one not). I get this infinite loading bug for DeoVR on both types of user profiles.