But do they actually work in F ?
(Answering my own question, there was a mythbusters that used a NASA piece of kit that was marked ni miles/hour .....)
Sadly, some do.
I think I remember reading one Mars mission failed to make orbit because the designers fumbled the conversion of imperial to metric. The fools had designed a space craft using slugs, ft/sec and whatever instead of the proper metric unites that they were required to use in the documentation they gave to NASA.
So when NASA used that documentation to make course corrections things didn't quite work out.