Maybe I'm stupid , but , heres something that puzzles me.
You have vac advance adding timing at low RPM and losing timing at higher rpm.
Then you have centrifical that adds the timing as the rpm's increase.
The two kinda cancell each other out ,if not make your timing jump around.
Mild to wild i've been running 36 locked and a adjustable vacuum advance if the engine , convertor combo needs it.
Seems simple and has worked so far.