I also find it annoying. Do wonder if the app can’t just keep a cache of the data it got last time it was connected and keep using that whilst it reconnects in the background. Not really any reason it has to show the ‘lost connection’ screen straight away? Usually connects in a few seconds, so in many cases you wouldn’t even know it was reconnecting.
Would there be a possibility to introduce a timer setting for this purpose? like 200ms-2seconds for instance?
Maybe the WLAN stack default timer is too agrassive?
I don’t believe there is a ‘legal’ api that will allow Roon to do this unfortunately. There are only certain activities that Apple will allow to be exectued in the background, depending on what your app is trying to do. And maintaining a network connection simply for the purpose of maintaining a network connection is not permitted.
It would be possible for Roon to do this in a sneaky way, however this could lead to the app being rejected (Apple is pretty strict about this stuff).
If the Roon app was classified as an endpoint, and actually permitted the audio playback of music on the iOS device, then it would be allowed. Music Players etc are permitted to maintain a persistent network connection of course 
Ok let me backtrack on my previous statement…
The iPhone app, which I rarely use, also reconnects when I bring it to the foreground, but it brings me back to where I was in the album or artist list, which is different than the iPad version (which starts from the beginning)
So perhaps this is a bug as opposed to a feature request.
Any moderator care to comment, or perhaps move this over to support to be addressed in a future build ?
I think the iPad behaviour has a bug report in. I’ll check the bug database and let you know.