Make Wifi Fallback work
Routers need to have a working WiFi fallback to make the upgrade of complex meshes possible.
When all upgradeable routers are able to upgrade via WiFi station mode there is no need for complex tracking of the mesh topology and a server-sided steering of upgrades.
The WiFi fallback module needs to be understood and tested extensively before deploying it to the routers and trying to change the Mesh Mode.