Replying to
@mhoye@cosocial.ca @neauoire@merveilles.town @Kehvarl@furry.engineer @cstross@wandering.shop I had to maintain a units library in a GIS system. Helping customers sorry out the problems they had from confusing feet and US survey feet took more of my life than I want to admit.
Also historically far from the only survey foot. If you have a systemic error in your survey data the easiest way to fix it is to change the unit.