There are two scenarios in which I use MMA2. 1.On the Orbsmart is MMA2 installed and on SD card (in the Orbsmart) the whole music library. The Orbsmart is connected via hdmi to an audio/video receiver. So I can listen to the music and manage MMA2 via TV display in our living room. That works perfect.
2. I had to install the teufel raumfeld app, otherwise the teufel speakers won't work (see other postings). But the raumfeld app can only stream to the speakers. It cannot play music from the Orbsmart via the amp as it is only for streaming to the teufel speakers.
As I'm using MMA and MMW4 for years I don't want to change and it is not a good option to use two apps for the same thing. The other thing is, the Raumfeld app isn't able to read the genres of the MM library. So I tried the casting function of MMA/MMA2. When I click the casting button I see the two teufel speakers wit their two IP adresses. I chose one, et voilà it plays the music (for some tracks).
But in this case, I can't remote control the speakers and have no title / cover display. (only in the living room via TV display, which is inconvenient when I'm upstairs in the other rooms.
Therefore I use The raumfeld app which shows the actually played track (by MMA2) and I can change the volume and click
pause or start the actual track again. If I would do this also via MMA2 it would be great but I think, that's not possible. And MMA2 also stops casting when I don't use the Raumfeld app6on the old mobile
The Raumfeld app is installed on an old mobile for the remote functionality and for "seeing" this mobile in my home network. The Raumfeld app is also installed on the orbsmart of the same reason.

MMA 2.1.0.1274 + MMW5 + Orbsmart S86 pro ( android 9) + Orbsmart remote AM1 pro + Nova-Launcher + Moto E22 (android 12) Teufel One M + Teufel One S + Teufel Supreme On Bluetooth