It would be a major update, but it would be kinda cool if we could choose a unit for the designer, and have all measurements in the designer follow that unit. For example, nudging parts would be in whatever unit you choose, same with fuselages, and basically everything else. Everything made after this update would be given a special mark in it’s xml, telling the game that it uses the new unit system and what units it’s in. All parts would stay the same size, just that fuselages and stuff would use the selected unit.