Specifics:
I have the mod "Beyond Home" Installed and I want to test how some aircraft fly. The problem is, the mod changes the default planet, so the gravity, atmospheric density, and aerodynamic forces are all different. I also have a world where I've done lots of thing with the planets in the mod. I don't know if removing the mod to work on planes with Kerbin in one world would corrupt another that needs the mod, even if I didn't interact with the modded world while the mod was uninstalled.