The inertia inherent in the imperial system is huge. We always work with a Registered Land Surveyors and engineering companies if any sort of map accuracy is needed. Usually they are our client, and they sell it to the end user with their stamp on it. If they just want "a pretty picture" of campus, or farm or whatever image of the ground they want, to hang on their wall, we don't get any ground control except what the airborne GPS & IMU give us. It is just a picture, not a map.
If they want to have a map, and meet the National Map Accuracy standards we require them to put down ground targets.
https://pubs.usgs.gov/fs/1999/0171/report.pdf
The targets are large white X shape targets that make it simple for us to see that point, and tell our computer this is X,Y & Z and accurate to a very high accuracy (sub MM) since they used a Trimbale GPS or some other brand that gave them super accurate measurement. We ask for a grid of them, in a pattern, and we will be well within the map accuracy standards.
In talking to many clients the centimeters, 1/10th of a foot and miles get all mashed together in the clients specs. Most high res jobs want a 3 inch pixel or a 0.25 of a foot, or a 7.62001524003048 CM (we usually round that to 7 CM for conversation purposes). We will make them in whatever the clients specifies. We will use Indian Yards (0.0833336339006011) or links (0.378788636365151) or Sear's Feet (0.250000933449327) or any of the other myriad of measurement systems.
In the end, we are NOT surveyors, and never claim to be. We sell the geo-referenced image to the surveyor and they are the ones presenting it as a map and accurate. I just finished a project that the deliverable is a 32.4 GB (34,886,586,530 bytes) tif file. It is a large area, at very high resolution.