The reason for a LOT of initial [ idle ] timing is the same reason you want to start the centri curve early. The big[ger] cam produces a less dense mixture at lower rpms, which means more ign advance is reqd.
The big(er) cam part, yes. The rest of it....are you saying that with the added initial timing that the centrifugal should be left alone except for limiting the total? As per my example, it would be 20º initial, keep the primary and secondary distributor springs the same...just change the limit (probably to 12º or so crank degrees)? 32º works in my engine just fine.
I'm wishing I had adjustable air bleeds in my 4779. At 20º BTDC initial, I don't think the engine is going to idle below 1000rpm. But...that's another matter.