ORBI

I basically just went thru and completed as of today a similiary exercise.  I replaced one router and several access points with the Orbi.  I have as of this posting 47 devices connected out of a possible 70.

You have probably completed this effort, but 1). I had exported my config from my previous router to get a copy of reserved IPs and Ports forwarded.  2). Just go for it and be prepared to make a couple round robins on the various devices to reconnect them.  3). I renamed my SSID so that made it a requirement I visit each device, which I wanted to anyway.  If you don't changed SSIDs, you might get lucky and everything reconnets.