High battery usage
On my Pixel 4 XL the app uses 10% of the battery per hour of listening. This is much more than Google Play Music (4.5%) or YouTube Music (5%). This is playing MP3s streamed over wifi from a server in my house.
I just installed this app yesterday, and while the functionality is great, I noticed the same thing. Even after killing the app, fully charging and rebooting my phone, it came back to use battery fast enough to make my phone noticeably warm. I had to uninstall despite really liking the app otherwise.
I'm on a OnePlus 6 with Android 10.
Mine uses a ton when casting. Must stop casting after a listening session so the battery doesn't drain, even though I'm not actively playing songs.