I would like Opus, but I’m using a subsonic client on iOS and my choice has been Flac (Alac?), MP3, or AAC. Opus wouldn’t play (There are some that supported it, but I didn’t like their UX).
You can give Arpeggi a try. It’s still in beta and Testflight only, but already (imo) by far the best iOS app for Navidrome/subsonic servers. It also supports Opus playback on current iOS versions (since Apple added native support for the codec).
