You assume I’m not using it. On the contrary, I use it a lot at work. We have some old TK interfaces. They take ages to load over the network. The interfaces load much faster when using Xvnc running on the remote machine rather than X forwarding (but it is not as convenient).
Yes, that is what I meant with not as convenient.
Your use case is covered by waypipe (which in my tests is much more responsive than X11 forwarding).
I think you are confusing stuff here. Which kernel has an embedded X server?
What part of your use case is not covered by waypipe?