^That. Just temporarily disable it via 2 //'s before that line and save the config and flash it over. This will let you do the changes and not have the main program preventing it.
//#define KEEP_SAVEFILES_WHEN_PROGRAMMING
Once you do the flash you can always go back and remove the //'s and flash it back in, or honestly just do like some of us do, simply leave it disabled if you’re gonna be playing around with the config for a while.
Basically you want it disabled doing a new flash and once you verify the saber is where you like redefine the line and flash it back in. *Again, or just leave it be. I’ve yet to ever redefine it in mine.