Per device (plex app instance?) content restrictions

I’m new to Plex and here is my use case, that I can’t make work.

My friend has all the Moomins (amongs other rare stuff) seasons dubbed in my mother tounge.

I could watch it on youtube, but quality is low, aspect rations vary, sound’s not great sometimes, few episedes are missing and there are ads (youtube on TV).

He’s got all Moomins in HD quality digitised, I dont know how, but those are not streaming anywhere and there is no DVD to buy and own. He is using Plex and he told me he could share his library with me so we could watch his stuff.

Plex is great, managed users with restrictions are spot on BUT managed users only see local content (filtered which is great). I can’t leave my kids using my full account with access to my friends whole library.

What I need is my managed (restricted) users, that are not another plex accounts, access to the shard library. Since I already know this is not going to happen, as the feature request is 10 years old, I have another idea.

Content restrictions set up locally on the Plex app on the main account. I would not need managed users anymore. I’d log in on TV with my normal Plex accout, set up restrictions and secure it with a PIN.

That would make my use case work and would not touch the controversial “I don’t want you to share my library with your “friends””.