First was, my version required a key combination to be input in sequence to trigger the video mode change from whatever the original was to roughly double the lines/chars, then turn off local echo, and up the baud rate from 1200 to 4800. And unfortunately I could not send these keystrokes over the serial port.
I had considered attempting some sort of ROM hack to enable these modes all the time but never went through with it (also my main ROM was soldered to the board, not removable like some later models)
Eventually what I did was use a Teensy uC and a system of optocouplers wired to the keyboard matrix that 'pressed keys' in the right order at the right time to enable the mode I needed automatically on powerup. Timing was difficult as if I attempted to 'press' the keys too quickly or exactly together it would misinterpret or drop the commands.
Now that the terminal would auto-configure itself upon power on, a Raspberry Pi 1 Model B running Raspbian in CLI-only mode with a wifi dongle was shoved inside it and hardwired to the serial port (with a TTL level shifter between it and the Pi's UART) and I had this setup running a few small programs I wrote to display weather, stocks quotes, 'screensavers' etc.
I had the unit on my kitchen countertop by my coffee machine and for a while would turn it on every morning to check news and whatnot. Something about it was just super satisfying; the limited information meant my morning coffee wasn't overwhelming- just the day's weather, a few stock quotes, and a few headlines pulled from the BBC. All with this super cozy glow on the white-on-gray CRT.
Unfortunately I eventually pulled it off my countertop and cannibalized the machine for other projects. The whine of the CRT wasn't something I wanted in my kitchen running all day. The little keyboard was cute but the keys made any lengthy input tortuous. And the power draw just for the nostalgia factor every morning didn't make a lot of sense when I have my laptop nearby anyway. I have no idea what the power consumption was but the little guy could put off some heat that is for sure.
Sadly practicalities won out over the aesthetic.