RBS850 Incorrectly Connects Powerline Adapter as a Backhaul on Power Failure

I have an RBR850 and multiple RBS850 satelites.  One of my satelites has a TP-Link Powerline WiFi Extender plugged into the Ethernet port.  This works to use Ethernet over Power Line to get a network connection into my safe where WiFi cannot reach.

This works fine, however, when there's a power outage the EoP comes up first and the Satelite never connects to the WiFi backhaul.  I beleive the Satellite sees the EoP adapter as it's backhaul and never tries the WiFi backhaul.

I've looked at the classic KB article on how to set up Ethernet Backhaul, but it does not address my issue.  In this case I need to somehow prevent it from using Ethernet Backhaul.

I'm in a rural area, and the power is sketchy if there's any bad weather.  If I am not home, I can no longer monitor the safe, and my wife, of course, calls me to complain that she cannot watch Housewives of Whatever City is popular.

I could use a delay on timer like this one, but the outdor box in which this Satellite sits is rather small, and it would mean I need to split the power - to the Satellite and to the EoP device, removing the space-saving benefit of just plugging the router into the EoP adapter as a pass-through.

Any ideas?