Now (my WiiM is on the Ethernet, while mobile phone on WiFi) I cannot really do anything in the WiiM Home app (on mobile phone): The WiiM device (in the app) is displayed as offline (from the point of view of the app). And rediscovery goes only through WiFi. So it looks that I cannot have LAN device and WiFi devices in the app.
Whole my home network started without WiFi at all. This was so till 2015 when I (maybe a little bit late
) switched myself from loved and best Nokia 6310i mobile phone to smartphone era. WiFi was only necessary for keeping my phone updated and also for my attempts of developing smartphone apps.
Only after slowly retiring myself I have started with development of home IOT and these small boxes start main usage of the WiFi connection while their central was/is securely kept on the LAN.
So why different networks?
I am from old school, remembering the time before Internet. For me it was (and still is) very natural to have routed networks, similar like having an extra firewall between Internet and my home network. (Safely ignoring crazy meshes like Philips bulbs etc.)
Additionally, at that time I was not interested in the "new" world of autodiscovery protocols that work only on 1 network.
Still one question is open:
Is the mutual exclusivity of WiFi and Ethernet on WiiM hard limit of HW, or limit of operating system used, or it is design decission of the application?