It appears I'm back up and running but I have no idea why.
I migrated my config dir to the new usb drive (also on 6.12.4) and started back, replaced my key, and now no matter how many times I reboot, the network-rules.cfg file remains in /boot/config. On the old drive, I could place the network-rules.cfg file in /boot/config and reboot and everything would work perfectly...except, after reboot the file was gone. When the file is present, the eth devices get assigned properly, when it's missing, things go wonky. Ghost in the machine I guess...
I ran a scan on the old usb drive and it came back with no issues -- so I have absolutely no idea what could have happened...but looks like we're back online now. Thank you for your help.
