Rack mount + locking plug would be tremendous improvements. Rack mount could be as easy as a set of wings with screw points on the chassis, and if the power brick was incorporated into the main...

@qkie the ER7212PC doesn't seem to have a standalone mode. I poked at it for a little while without success, then finally ordered an ER7206 to replace it.

An update. It looks like Option 12 (server name) is getting set in place of option 66 (next server). Wiresharked results sent to TP support, sadly it'd definitely trigger the 'illegal link in...

On the latest non-beta firmware on an ER7206 in standalone mode. Option 66 is set to x.x.x.46 Option 67 is set to the correct .kpxe file (whose name i can't post due to the forum software thinking...