My goal is to make GTK backend support runtime-switchable. So you can for example move your windows from an X server to a Wayland display.
And once we can do that, we can also switch between X servers or Wayland servers. And at that point you can support something like screen for GUIs, so you don't need to shut down the application when you log off. Or even better, move the application to broadway while logged off, so you can connect to it from a web browser and see if it's still doing what it's supposed to (say a long running rendering in Pitivi) and act on it from your Galaxy phone.
But no, we're not there yet. But it shouldn't be too hard if someone wanted to spend a few weeks on it.