Any way to change binding for Fatal Blow?

[Jeremoople]

I know modern MK is made for standard console controllers, but arcade controls are still more fun. I have multiple fightsticks (I build them as a hobby) but most of them only have 6 action buttons which means they're unusable for MK1. MK9, 10, and 11 could be worked around, but now I have to save a button for kameo. So with two punch buttons, two kick buttons a block button, and the kameo button, all 6 buttons are occupied. I can still do grabs by pressing punch and kick together, but I need the stance flip button (which has no other purpose) to activate fatal blow.

Having to use a normal controller isn't the end of the world, but I'm curious if anyone has a solution to this.