A much worse problem with this keyboard is that you almost cannot buy even regular MX-compatible keycaps for it, because the system76 people chose a really nonstandard physical layout. 1.5U Caps Lock, 1.5U Delete in the function key row, 1.5U Backspace in the number row, 1U backslash in the QWERTY row, 1.5U Enter in the ASDF row — these keycaps don't exist in most sets, except in some “40%” or ”ergo” addon kits (and even there you may not get the exact legend match for some of them, although for Caps Lock that may be a feature). 1.5U Shift is also really rare. So if you don't like the stock keycaps (which have the uniform XDA profile, and some people just don't like it), replacing them would be hard and/or expensive.
So it is possible to reboot into the firmware update mode just by sending some bytes to the raw HID interface. Apparently they did not think about the security aspect of this feature.
