I hope this isn’t considered as spam. I just made a forum account to say thank you to Tolriq for the work that went into Version 15!
I have kind of an oldschool use case where I use my old Onkyo receiver and cast to it via DLNA with Navidrome as backend.
Previously, I only got casting to work with the “Proxy via Symfonium” option and only FLAC and MP3 worked.
But i started archiving my music as Opus and that wouldn’t work on my receiver at all, no matter what I tried.. But with the latest v15 beta form the play store, not only does DLNA work without the proxy setting, but Opus also gets transcoded to mp3 on the fly now and plays on the receiver!
So again, thank you very much @Tolriq for your work - much appreciated 
Enjoy your holiday!