Sharing a subset of Home accessories with kids

We have many HomeKit accessories in the house. My teenage kids have HomePods in their rooms, and I'm about to install compatible lights there too. They do not have access to our "home" in the Home app, because it appears to be an all-or-nothing thing. I don't think they'd do anything mischievous but I can see them accidentally messing stuff up.

Am I understanding right that there's no way to share a subset of accessories with someone? (I see "guest" access, but that looks to only allow sharing of locks, not other accessories.)

I'm considering setting up a separate "home" for their stuff so they'd only have access to their own things. Would that allow cross-home automations?