Reboot to DFU?

but so far your argument was that it is dangerous - someone with access to console can remotely update your device so something physical (holding button) to enter DFU is safer.

Yes, I know... I'm just getting worn down over time :)

I guess there's an argument that it is now possible via the CLI to actually rewrite the bootloader from Espruino (once you disable the write-protect), so in a way if you really wanted to screw it up from the REPL you could.