That's very cool, but just to point out: that's not JTAG, it's serial (UART).
JTAG is a much lower level protocol, typically used for hardware or low-level software debugging. Serial/UART gives you a command-line interface to the software that's running.
Using a JTAG interface is a lot more complicated. If you're interested in playing with it, check out OpenOCD.
There's a bunch of train video channels on YouTube (because, of course there are). I love throwing on something like [1] just as background while I'm working.
I know there's already Imperfect Foods, which uses a route delivery model rather than traditional shipping. I haven't tried them, but I'm considering signing up.
Assuming you're running the full version with the supervisor and add-ons, I'd recommend the Home Assistant Google Drive Backup add-on[1]. You can set it up to take snapshots on whatever schedule you like and keep a rolling backup in the cloud.
Restoration is now part of the new setup workflow, so you'd just flash a new SD card with the base image, and upload a snapshot as you go through the setup process. Poof, everything's back the way it was.
JTAG is a much lower level protocol, typically used for hardware or low-level software debugging. Serial/UART gives you a command-line interface to the software that's running.
Using a JTAG interface is a lot more complicated. If you're interested in playing with it, check out OpenOCD.