Yes your right about advance and igntion, but you have to think about bore sizes, quench pads, and all the other variables. Also again your going to the extreme, under light loads/high vacuum situations you can add more timing and gain econ with no draw backs. When you throttle in that timing goes away and your back into the "safe zone" on timing.
depends what your curve right now? what is the number on the vacuum advance canister? at what vacuum is the can coming in at?
