A couple things, ONE I have no vac advance, so a high initial is compensating a lil
Two, full advance happens pretty much as I'm going releasing the clutch@2200 @ and going WOT from there=max power.
Three, The car is faster,torquier with a high initial, which helps in any combo, especially when the combo was slightly compromised by lack of gear OR the right intake design, OR too big of a carburetor OR when the carb blades are open too far to get it to idle, by raising the initial you can now close the blades more to get the slots right in relation etc.....