Roku has a Jellyfin app.
Roku device locked down with parental controls + Jellyfin app connected to your server + a non-admin Jellyfin user account so they can't click all the buttons.
The Roku aoo isn't great for my use because it's stripped down. Maybe a benefit in your case.
I like to think there was a specific person in Nebraska the author had in mind. The University there had a tap into the ARPANET back in the day and always had interesting projects going in that one wouldn't typically expect in Nebraska.