...and then all you would have to do is retrieve the exact metes and bounds legal description for every separate parcel of real estate in the United States and re-write all 100 Million or so descriptions based upon your formula. Once you had done that, all that would be left is to contact the holders of all interests of record for each parcel, obtain thier written concurrence and record a new description for each. Simple, actually.
Ha ha or you could leave it the way it was. There's no reason some English could be used, just because its a pain to switch. Or computerize the entire process, it would be monumental but would end up saving time in the long run.
Just do the conversions when the property changes hands. The new deeds would have the new measurements. It wouldn't need to be done overnight, and converting every parcel of land in the country could take a couple of generations (land doesn't necessarily change hands every day).