After all the effort I put into fabricating a hybrid kick starter I am back to OEM. I scored a cheap used OEM kdx kicker on *bay. It came together with the knuckle, but like all old kickers it was very sloppy. Once they get sloppy, they tend to bend the washer and circlip that keep the pedal from slipping off the knuckle. I put a brand new washer and circlip, and within 3 kicks they were bent again. So I tossed them in the trash and got a big fat washer at the hardware store. It is about 5mm thick and its I.D. is just slightly bigger than the knuckle post. Top of this fatty is flush with the top of the post, which is where I welded this puppy. It ain't coming off now! While I was in there, I put a blob of weld on the contact surfaces between kicker and knuckle 'cuz it was badly worn. Then 5 minutes with a file to shape the blob into a flat contact surface.
IMHO the OEM kicker is much more comfortable to use, and doesn't destroy my boot. It is still a sloppy fit on the post, but who cares!