I’m trying to use Yatse with Plex and Chromecast to my home theatre system. I can’t see any way of achieving gapless playback with this setup. Is this correct and, if so, is there a solution in the offing?
There’s no way and no efficient solution for that sorry.
Chromecast does not support that and Plex does not implement necessary workaround.
Doing that on the phone would be highly inefficient and sources of problems.