This is great! I will be playing with this.
It doesn't look like there's support for multiple logins/profiles in channels yet, is this something you're considering? I usually hate multiple profiles but for kids it might make sense so they don't just bypass and watch whatever they want. Or another "app" in ATV for Channels Kids they can click and be presented with only the kids stuff. Then no one has to worry about logins (and I could use ATV profiles to lockdown if desired).
Also, I've been fighting PLEX on how to properly setup a kids library with only specific content. Basically I have a library full of kids content that I'd want to import as "kids" library content. Then from my other libraries I'd want to mark individual items as both kids and main library so they can watch in kids area too. The issue is PLEX primarily uses ratings which don't work for kids, as we don't want them to watch X but think Y is ok, regardless of ratings. Either because of annoyance, personal preference, etc. PLEX has shared tags but they cause other issues.
Can't wait to try this out some more!