Here is another way to fire the fusee. I'm using a "logic gate SCR". Advantage over a FET: cost, short duration trigger, trigger directly from PIC or decoder chip. This SCR is rated to deliver an 80A pulse lasting 10ms. I'm guessing that at >20A, 220W the fusee will not take very long to blow.
In the simulation, light blue is the trigger pulse from the logic. Dark blue is the voltage at the anode of the SCR. Red is the current thru the fusee, and green is the power dissipation in the fusee.