How is your throttle response just off idle with the timing that late? You're getting into the area where a bog or a backfire might happen when pulling away from a stop. It might be worthwhile to restrict the centrifugal advance a little and make up the difference with initial. I used to do that on small block Chevy hotrods with moderately radical cam timing- - - -reduce the centrifugal advance about 5-8 degrees by limiting the travel of the weights, and add the same amount to the initial setting for good throttle response. Total timing doesn't change, it just gets rearranged as to where it enters the advance curve.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!