Streaming on Yamaha MusicCast devices

Hi,

after over 10 years I'm looking for an option to move away from Spotify and Deezer would be my first choice. As a complete beginner using the service and the apps, I do have one question regarding the support of Yamaha MusicCast devices. I've got two at home, which are the main devices for me and my GF to listen to music and that’s not going to change anytime soon.

Both devices support Deezer next to several other services, and I noticed that I can login with my Deezer account in the MusicCast app and start streaming, however, I'd like to avoid doing it like this, since I'd prefer to use the features of the Deezer app and not rely on what Yamaha gives me, which is comparably limited. I'd like to use the Deezer app directly but switch to different outputs, other than my phone. At least this is how I know it form Spotify (don’t know about other services), so you use your app more or less like a remote control and the Yamaha device streams directly, without taking the detour via the phone, say, with AirPlay or the likes, which is really inconvenient for several reasons.

Using the Deezer app (iPhone), I cannot see an option to chose the Yamaha devices as "Audio output". When I maximize the currently played track, at the lower left there is this speaker symbol and I'd have expected my devices to show up there. At least it's similar in the Spotify app. My question is, is this supposed to be like this and do the devices not (yet?) show up for some other reason or is this just not supported? All are in the same LAN/Wifi, as is my phone, one Yamaha is using Wi-Fi, the other one is wired, but both can do both, if required (R-N60, WX-030)

I'm currently on Deezer Duo (trial) plan, in case this makes a difference.