"Well, there is a port of glibc to UEFI, so one could very easily "boot into Emacs". Strangely I've not seen anyone do this."
Can you hook me up with that link :) Cheers.
Back to topic: inability to distinguish O and 0 seems pretty terrifying for avionics. Related, I love SF Mono, but it's so hard to read 0000080 in small fonts (try it).