I have been following the progress of Field Station 42 an open source program.
It allows you to create live tv channels based on genres or content or original airing channel, or holiday, etc. and make your own live tv box with channels. Your own personal tubi with your own content.
I would love a feature like this built into plex where i can create my own live tv channels based on various preferences. There is something magical about tuning into a station and being surprised by an episode you haven’t seen in awhile.
Here is a link to the website that explains more about it.
If you haven’t already, you may want to check out ErsatzTV. It provides the functionality described and can integrated with Plex Media Server via Plex Live TV & DVR (you set it up as a tuner).