Sample Bluetooth service classes collected from my JBL Flip 4. (don't buy JBL, kids)
The main one to filter for is AudioSinkServiceClass, which allows us to play audio.

00001108-0000-1000-8000-00805f9b34fb - HeadsetServiceClass
0000110b-0000-1000-8000-00805f9b34fb - AudioSinkServiceClass
0000110c-0000-1000-8000-00805f9b34fb - AVRemoteControlTargetServiceClass
0000110e-0000-1000-8000-00805f9b34fb - AVRemoteControlServiceClass
0000111e-0000-1000-8000-00805f9b34fb - HandsfreeServiceClass
00001200-0000-1000-8000-00805f9b34fb - PnPInformationServiceClass