FBO plate over advancing

PRH said
I used to braze up the slots and file the length as required.
Seems like most distributors I messed with had the slot plate marked something like 15(30* at the crank).
If you limit the travel of the pin to about 1/2 of what it is stock, it should get you close to 15-16* at the crank.

That's essentially what I did but using a mig. Then filed out to 14deg (0.460 slot length)

I think the posts being referred to are the posts that fit into the adv limiter slots. If they are "grooved" then the weights would move too far.