Oolite uses the metric system, so I think it doesnt make sense that a professional crew would say something like that.
In fact, I believed imperial units to be used only as a archaism(?) by mudcrawlers in some backwater systems such as Phekda (eh? Dylan?) and possibly by the Duvalians, but that's beyond the point...
You know those who, having been mugged and stabbed, fired, dog run over, house burned down, wife eloped with best friend, daughters becoming prostitutes and their countries invaded - still say that "all is well"?
I'm obviously not one of them.
I feel archaic Units of Measure are perfectly fine...to give characters some character... I fully expect feudal and especially alien planets to have their own SI-systems.
However Galcoop would most assuredly enforce a uniform standard for anything related to ship-building or navigation.
(such as a base 10 numeric system and a distance unit based on Lightspeed or more likely the size of the hydrogen atom or somesuch universally fixed value. (as lightspeed is dependent on measurement of time AND space.)
A good way to have a character feel stubborn or set in his ways (or a mudpuppy) is to have him/her insist on using his/her native UoM.