I change from a 50t & 39t 130 bcd Shimano 105 standard crank to a 50t & 34t 130 bcd Shimano Ultegra bcd compact crank as often as I want. I just remove the left hand side crank arm, slide the crank off and reinstall. It takes 10 minutes and I don't have to adjust the derailleur’s.
So rather than keep then keep the compact on and simply change one ring, you change the entire crank? Sounds like a lot of work for nothing.