I have an 8 and a 7 year old who both have their own steam accounts as child accounts within my steam family. Both of them have access to a profile on the steam deck(though I have 2 decks so they can each use one at the same time) and they for the most part just work.

The steam user profile changes but the account the steam deck runs on doesn’t. So some things stick around. Controller pairings and the like just work. Steam profile specific configs need to be done multiple times for each user (steam input custom mapping, etc) but I try and mostly stick to deck verified games for my kids because they really do just work.

I had a dock for a while and it also just kinda worked. But I didn’t have to do much tweaking. The dock broke after a while though(jsaux not valve) and I never bothered to replace it since I ended up just installing moonlight in my tv and sunshine on my gaming PC(also Linux).

I don’t have any experience with heroic launcher, but I did set up prism and Minecraft on their profiles and it just worked with the right deck compatible mod bundle.

The biggest issue I have found is sea of thieves will default to whichever the last signed in account is on any profile, so I just signed into it on my daughter’s account and don’t play it on the deck myself.

Docking it made it a bit more complicated for us as well, mostly because the kids don’t know much about the tv inputs and honestly getting them set up would just take me a few seconds to turn it in, grab the charged controllers and get them to the home menu so I never really bothered to teach them it. But that’s a non issue unless I buy another dock at some point in the future. They both prefer to be in mobile mode on the couch anyways.