Does anybody really use the steam deck with multiple users and can tell me what I'm doing wrong?

I got the mid range deck, enjoyed how I could play almost my entire library and created a steam account for my oldest son so he could use it, too, without us messing up each other's save games or stats. I set up family sharing for our accounts and added some games to the family library, but from that point onwards the experience has pretty much been a mess for me.

First of all, setting up the family sharing was pretty much a convoluted process where I really didn't understand what I was supposed to be doing... Were the family PINs supposed to be the same for both accounts? Who selects what in order to get the young man to play skyrim? It was all weird, but we eventually managed. The result is, however, an annoying setup that is just weird.

• When I turn on the deck, it now always starts in family mode on my account, so I always have to enter the PIN before doing anything that is not playing a game that I added to the family library. Which is most of my games. Shop won't open before I enter the pin, nothing works while being in family mode and it always starts in family mode.
• Considering how often I have to insert the family PIN, it's annoying how buggy the keyboard is with the PIN entry form... Every time I enter a digit via the touch pads, the keyboard just freezes for a second or so. No idea if that has something to do with localisation or something.
• Starting a game won't ask for the account... I have both accounts set up on the deck, but unlike e.g. the switch, the deck always starts games on the account that was last logged in, no questions asked.
• There is no proper separation of data for each user. When I added vampire survivors to the family library and he started it on his account afterwards, the first thing that happened was a hundred achievements getting unlocked because his game simply loaded my state. Same for other games which just show save games from all users, which is super annoying for the usual auto save and continue game flow.
• He says he can't really chat or play games in multiplayer if he's using my shared games on his account... No idea what's going on there, have not yet gotten around to trouble shoot that.

Am I doing something wrong or what is this? We had the deck with us on our last vacation and with the Internet being just not available a lot of the time (which is imperative to switch accounts) and all those issues outlined above, it basically got no usage at all and I'm getting more and more annoyed by this.