The MAC valves are good I've used them on standalones before... and I don't see why you can't use it as long as you completely retune the ECU to use it properly.
The MAC will most certainly operate at a different frequency then the original N75, the pintle reaction times will be different... so it's not going to be just a pnp setup.
Can you adjust the freq value in the flash? I would like to think Bosch would be smart enough to provide a variable that can be adjusted just in case of a product revision or using the ecu on another system all together?