Okay. What you are really talking about is a sort of hybrid system of manifold vac AND a re-curved mechanical advance. I can see where that could be an advantage on some particular applications. But without the re-curve in the mechanical advance, that would still leave the timing drop off with throttle. Which I would think would be noticeable in at least some instances.

Maybe the biggest hurdle in dialing in your 'hybrid' system is in trying to control the amount of advance that the 'can' brings in. There used to be cans with different amounts of advance, but I don't know of many choices for them nowadays. And for a complete burn, light load cruise may want a different amount of advance than the idle wants forcing yet another compromise.

For my part, I set the initial as much as possible to the point that it does hit the starter. Just not enough to hurt the starter or to keep it from starting at all. A big capacity battery allows a few more degrees of initial than lesser ones. With one of the newer smaller starters and a 930cca battery, I can usually get about 24* initial and keep the cruise advance where the engine likes.

Keep us posted on your system, it will be interesting to see how it works out. Come on spring time!