Hi Ray,
I had looked at that, however those filters are for the old bend mags that did not have internal capacitors, or so I believe. Adding capacitance might work but what are the negative effects on the points.
One of the good folk at Dynon has reminded me of capacitive D SUB filters, which I have used in the past for other avionics (early D10's that put out radio noise) and industrial automation jobs.
Thanks for the thought, and if you know more about doubling up capacitors on magneto's let me know, because adding one in parallel will add the capacitance.