Just a faster curve with lighter springs will hold it off the stop so say idling in gear at 28 (so 9 mechanical advance in) with another 5 mechanical advance to go as rpm comes up.

without driving you can test how it will respond to more in gear idle advance by advancing it till you have 28 in gear and fiddle with idle see how it likes it I know this would be 42 total but at this point your not driving just finding a nice idle.

Then you tailor you advance springs to get it to idle at that advance but still have your 33 to 36 total.