This very simple homebrew just flips the number in emummc/emummc.ini that determines if Atmosphere should load emuMMC.
Removes the need for SD pulls to reboot from emuMMC to sysMMC or vice versa if using fusee-primary.
Open the .nro using the HBL.
Press - to toggle emuMMC on or off.
Press + to exit the application.
Don't attempt to toggle emuMMC if it says something is wrong. That's bad behavior.
Dax for recommending simpleini library.