I asked about similar thing in other post and contrary to @tmm1 said, what I am asking is not the same thing as PlayOn. I never mention PlayOn in my post.
I don't see any technical limitation or God-imposed rule preventing implementing that, since you already access TVE by own minimal Google chrome core that simulates user authentication to the webpage in the background.
The same as "importing movies" to own library. Movies are stored in other directory, this is only reference in Channels database to display them in Library. YoutubeTV, despite claiming "you can DVR" stuff is in fact all on-demand because it records everything for you and stores on their servers but I assume you know that already so there is no difference nowadays between DVR and VOD - it was during analogue times when we record stuff on tapes.
looks that I finally have to start developing promised tvOS client for Jelllyfin and maybe someone from their community will help to replicate TVE+VOD functionality, we'll see.