Oh my God I have a story about this.

Our entire company wants metric. The guidance folk want to do their modeling in metric. The prop team wants to do fluid/thermo in metric. The structures team wants to do load analysis in metric.

But the boys at the 'pad are imperial only. The water system, fuel tanks, all ground infra is in imperial. If someone runs down to the hardware store they can easily find a fitting, gasket, or o ring in imperial. But metric? Good luck.

So our company decided to support both. The flight computer and ground software did unit conversions, everything was unit-aware, telemetry was occasionally manually converted because the onscreen wasn’t the right unit. We had written our own turing complete, inhouse programming language and we ended up implementing dual-static typing. We had float, int, bool and then we had units where some operations required the units to be the same thing. So cm and inch but not inch and kilogram.

The project was terribly mismanaged. To this day some still wonder why.

After we lost that one expensive spacecraft we’ve been moving towards metric more and more there as well.