You won’t be able to remove the WiFi credentials if you wish to have the Roam available in your setup. Just wire one of your players to the router and reboot the remainder if they do not switchover to SonosNet by themselves. You can check that, as each device will show as WM:0 in the ‘About My System’ area of the App rather than WM:1 etc.
When the Boost arrives, try adding it to the system unwired (use ‘Add Product’ in the App) and then simply swap it out with the wired speaker and put that speaker back to where it was before.
Set the SonosNet channel so it is 5 channels away from the hub/routers 2.4Ghz channel if your mesh system allows for that.
All being well, then everything should be fine.
There is actually a FAQ that covers this: the wired and wireless modes FAQ.
Basically, your plan seems solid, although if you can wire a speaker, you may not need to get the BOOST at all.
Switching to and from SonosNet will be automatic. Give the system a couple minutes to work through the details as you wire or unwire.
Give BOOST some space. Allow about 3 feet between BOOST and other WiFi gadgets — especially the router.
Thanks to Ken, Bruce and buzz. All qualify for Best answer so I’ll give that to Bruce who knew there was a FAQ.
I will report back on how I get on.
So this is how it went!!
The Boost was coming today, but I thought I would get the system onto Sonosnet by wiring my Amp to the ethernet connection on one of my two Mesh extenders (neither of which are wired back to the Router).
This worked well in that everything moved to a status of WM:0. But the system was none too robust, no doubt because the Mesh extender only had a wireless connection to the router.
The Boost arrived and was set up unconnected by ethernet I then removed the ethernet connection to the Amp and connected the Boost to the router by ethernet. Now the Boost and my generation 1 Sub went to WM:0 and everything else went back to WM:1 (my Roam was powered off and out of this equation). I waited and eventually rebooted all of my other devices, Amp, Play 5, Five, Beam and Port and still they stayed at WM:1.
I removed my wifi credentials from Sonos and rebooted the devces again, still no change but I went out for a couple of hours hoping they might make the move, but still no change.
So now I messed with managing the Network settings until I discovered this was about adding the system to conventional wifi so I abandoned mid way through this which resulted in losing all devices apart from the Sub and Boost from the system. The process in the app to find missing units failed.
So now I went round factory resetting each missing item and adding them back to the system. This worked well and with the Roam powered on, all units apart from the Roam were at WM:0. Fortunately the Roam seemed to have retained all my various favourites and Sonos Playlist dating back over more than 12 years!
I imagine that I might have dug myself a bigger hole to climb out of than was necessary, but all seems to be working well now.
Thanks again.