I decided this morning as I was very bored so decided to segment Roon to its own VLAN and move all my RAAT endpoints and Squeezebox Radio on to this. As I have a Unifi network doing this is all very simple and remotes connect with no issues even if they are on my standard VLAN which my phone, tablet and laptop are. Only issue is you loose the option to configure Roon on those devices on the main vlan such as my phone, unless they where configured before switching them over. My phone no longer shows up as a device to configure as I never had the need to add it, but my Hiby R5 DAP which was configued as a zone before the switch still works as a zone even if its connected to my regular VLAN.
So now Roons isolated from my main network, chromecasts are too, but all apps see them from what ever VLAN and wireless netowork I am on, except the IoT one which does not talk back to anything via the network.
Does it improve SQ as some claim? Not that I can tell but Roons so chatty on the network anyway its likely to not make much difference. Will it improve its performance overall? Who knows only time will tell on this. One thing it does do is keep vpn traffic away from it when I am working and I like the segmentation side of things makes for easy management of a larger network.