A pound is still a pound on the moon, since it's a unit of force not mass. It just requires more mass for a scale to measure that force. I'm an engineer that works on spacecraft, I know units, and hate the imperial system and all the conversions I have to do

Edit: and it's still useful to differentiate between mass and weight/force, just depends on the context. A doctor would want to know an astronaut's mass to accurately track health. But writing up a fitness plan to maintain muscle mass and bone density, force/weight is more relevant because squatting 100 kilograms on the moon isn't as useful a metric as setting it to a specific force in pounds/newtons