I have a theory that if you go to Microsoft's website Xbox: play anywhere, you can install KSP on your PC/Computer for no additional price and add mods into the files. I'm not sure if this can be SAVED on your Xbox KSP but, then again, this is a theory. I'm still in the development of testing this and am not sure if this is going to work or not but i am confident. Please try this out if you can.