Sounds like you are running plenty of initial although there are many factors that determine this and unless 2 motors are built identical and in the same car and conditions every engine has it's own magic number. More spark lead or advance at idle will allow an engine up to a point to run cooler but also cause hard slow cranking of the engine especially when hot. This was part of the reason back in the day that people would use manifold instead of ported vacuum for the advance. This way the motor when cranking to start will just be at initial advance but once running and idling the Vacuum advance would kick in to whatever setpoint you installed and keep the engine cooler at idle. There is a lot of debate about running it either way and I myself feel that for a mild street cruiser ported is best for more power under light load/ throttle angle cruising and fuel mileage of course unless you have a temp problem in a modified car that cannot be solved with all the usual means. For an all out motor where wide open total horsepower is king and things like part throttle cruising response and fuel mileage mean nothing you don't need no stinken vacuum advance. Our motors can tolerate a lot of advance in lite load partial throttle conditions and the vacuum advance accomplishes this raising both power and efficiency under these conditions. It sounds like you know what your doing with the timing and I'm sure you know you can't advance initial without affecting total which is a surefire way of smoking rod bearings and motors. I just found this on Rocky Rotella's site Haven't read all the way through so hopefully it doesn't contradict and make me look like a fool https://www.pontiacv8.com/articles/2018/9/30/blrwa28r1tb0vt5c24d7ejwjskxfdq