Hello,
Some of these things might be on the roadmap, but I wasn't sure. I noticed when I paired my phone with a car recently that no information came over the Bluetooth from JRiver. It did when I played with MO4 Media, VLC and Spotify. I'm thinking this has to do with the some of the below:
1: when music plays in other apps, my whole lock screen changes to that cover art.
2: When I use JRiver, I don't even see cover art in the notification. If I open the app, I do see cover art. Sometimes I see cover art. I'm guessing it needs to be embedded to show there, but since it shows in the app, I think it should show here.
3: When I want to use the notification to change tracks, pause, etc, I always need to do multiple things. The notification is minimized, so I have to pull it down. I think I probably did this when I first installed it and the notification wasn't functional, but I can't seem to make it act like the other media apps.