Did a little mallet testing of my own with primed cases and the springs and FP I had on hand.
CZC extended FP with rami FP spring - ignition with mallet. I can confirm that, with the 11.5lb mainspring, the hammer rests on the slide, and the tip of the FP extends past the hole.
Stock FP with rami FP spring - NO ignition with mallet. This might be the best scenario, as the tip doesn't extend past the hole, but the hammer is still resting on the slide with a 13lb mainspring. This setup lit off CCI with a DA pull.
Stock FP with stock FP Spring. - NO ignition with mallet. The stock FP spring does hold the hammer off the slide however (if it matters). Even with a 15lb mainspring. This setup lit off CCI with a DA pull. DA pull was 8lb.