as mentioned above from other users: I am interested in the upnp-feature too. I am using firefly mediaserver for more than one year with two roku soundbridges and it works great.
Now there are available some internetradios for less then 100 EUR with a built in speaker, so they are affordable now (in the past you have to pay 200 EUR and more for such a WLAN radio that can play my MP3 files over the network with a built in speaker).
I would like to use my new dnt IPdio Internet Radio as well with Firefly Media server, but the box supports only windows fileshares and upnp 🙁
So it would be great, if Firefly supports upnp too…
Thanks a lot for implementing upnp!