A slight inaccuracy: the flight strings are not x86, but ARM, running on a custom board.
Also, only the actual graphical display application uses Chromium/JS. The rest of the system is all C++. The display code has 100% test coverage, down to validation of graphical output (for example if you have a progress bar and you set it to X% the tests verify that it is actually drawn correctly).
> but I would not be surprised if you could power-cycle all displays if needed in the middle of a mission.
Indeed you can, judging by the instruction to power off and clean all displays (then power them back on) prior to ISS rendezvous/docking in the live stream.
Also, only the actual graphical display application uses Chromium/JS. The rest of the system is all C++. The display code has 100% test coverage, down to validation of graphical output (for example if you have a progress bar and you set it to X% the tests verify that it is actually drawn correctly).