It's all pretty safe, I think. Especially while still within the 30-day return policy.

The interface seems to only allow commands that could otherwise be issued more cumbersomely using the remote control. So there's not likely to be anything that could brick it there, at least not on the "uart" setting.

I have accidentally issued the "reset everything" command a few times now.. Bloody nuisance that, but at least I've also now got a script to restore most of the settings afterwards.

Still hunting for the codes to manage the 120Hz settings, though.

A useful pair of codes are the "power on" and "power off" commands, which my MythTV box is now happy to issue on our behalf. If we could also find the 120Hz ones, then the TV remote control will become completely unnecessary, and could be removed from the coffee table.