Well. I thought I would share.
I recieve the two new EX63's. Added them to my home network with the two EX75's without any trouble.
Waited about 1 hour expecting everything to sync. Even did a firmware update on the 63's it wanted.
Then went to the FAQ page and wanted to double check my understanding of the procedure to "promote" one of the 63's to be the Main, so I could remove the 75's in a day or so.
Although all 4 were in a state of "everything looks good". I started the change process. Followed every listed step. BUT didn't work.
All four node, remained in "RED" light condtion. WiFi never came back up.
I tried a variety of things. Turning off the new Main, and hooking the old Main back up to the router. Nope
Shutdown the old Main and hooked the new Main back up to the router. Nope.
Shutdown everything, including router, and slowly brought everygthing back up. Nope - Nope means RED lights across everything.
I even tried each of these steps an extra time, just to avoid a system reset. Nope.
I finally gave up, reset the new Main to a Freshly stood up Deco router, with the original SSID, and lost all of the client name and reserved MAC/IPA that I had loaded. Added the second node and placed it in the garage.
Then sat down to rebuild the 140+ clients' friendly names from my Excel list. and the reserved addresses the 3D printer other stuff needed the reserved addresses. This took just over 3 hours with the smartphone because unlike ASUS, the browser access to the routers don't allow us, to copy and paste Friendly names into the name space.