Multi-screen

I think there should be an option for multiple screens in the user settings.For example, João has a limit of 2 simultaneous screens.Maria, 3 screens…Because I have cousins for whom I have to create 2 accounts for them and one for their child.Or we could register one account linked to theirs as a sub-account and authorize access.They would just switch the account and the sub-account linked to their account would appear on the screen.I had to create 4 accounts for my aunt, one for her, my uncle another one, and for my cousins.My account has a limit of 1 user per account. If it were possible to select the quantity for each account, it would be better since not everyone uses just one screen.

I don’t understand what you mean by this. You can have upto 15 users if you are using plex home.

Plex doesn’t have a limit for the number of devices/screens a user can have their account on.

Let me explain. I gave my cousin a Plex account, but his account is open to all content while my nephew’s account is only for kids. I had to create two accounts; he needs to log out to access my nephew’s account in the living room. Could you add the option to have an account as a dependent under the same invitation and just switch the user on the user switch screen? And in the same place, show the number of screens per user: João 2 screens, José 1 screen. This way it would be better for user control.

If your cousin has a Plex pass, they can invite regular Plex user accounts (like their kids) into their own Plex Home. This will enable Fast User Switching.
https://support.plex.tv/articles/categories/features/plex-home/

The way plex works you have to specifically share with a user. There isn’t a method to allow your cousin to share with their own kids. There is a feature request to allow this but plex has mentioned it is not something they will likely implement. So you will need those 2 accounts no matter what.

As Ottokerner mentioned, your cousin could get a plex pass which would allow them to add other plex accounts to plex home and use the user switching feature.