Segregate Change
Change is bad in the world of programming. Simple changes on paper might be hours or work in actuality based on how the code has been written.
Rather than fear change, embrace it. Roll out the red carpet and let the change take its place in the spot light. Change is the star and needs to be treated as the Diva it is.
When you decide to give change the center stage, you will be more prepared to deal with her high maintenance, rather that make adjustments on the fly when she demands it.
She should never associate with her public and she does not want to either which is why problems will occur in the future when if you force her to be inline with the others.
Rather than leave a ticking time bomb in your code, isolate it and allow her to be composed within your system as just another actor.