I have over 50 Wyze cameras.
I share them with other accounts.
Note that shared accounts can’t view the SD card recordings, only the live view and Cloud recordings. You could share the credentials of the primary account, but then what happens if someone else changes the password and you lose access? I’d really only share account credentials with a spouse.
I have never tried viewing all 50 at the same time, but I have gotten up to 30+ livestreams at the same time (I think I’ve gotten 20 at the same Time on Wyze’s Web Portal and 30 something on the same monitor using a 3rd party RTSP converter), though not directly in Wyze App itself though.