> Chromecast support is flaky. Most of the time when I cast from my Android phone, the app immediately "forgets" that there's something playing back on the Chromecast (even though it's still connected to it), so I can't control playback at all. It's also hit or miss if the Chromecast will successfully play the media if Jellyfin decides it needs to transcode it.

This might be more the Chromecast's fault as I've had a similar experience with Plex.