Just want to say for searchers who find this thread like I did... this totally worked for me.
Dropped the node, added it back.
Firmware updates must have made AImesh stuff a little better since I set the system up some time ago, because it went smoother than before (didn't have to dance around with multilple tries and trying to "hit the window" of a timeout on the node).
As soon as it came back, my full SSH setup (BitVise client FTW) for the primary router worked perfectly just with IP address change. This definitely wasn't the case before, it was refusing any kind of SSH login method.
I will add that I poked around, and it seems like some other things may have changed?
The master router ALSO pushed out the scheduled-reboot settings to the node. Without me doing anything it has exactly the same reboot settings as the main router now (and I set a weird hours/minutes time for that so its easily identifiable as being pushed out.
Config = Merlin on main router, ASUS FW on the node, based on recc's around here that for nodes non-Merlin is fine/preferrred