No on the vac advance; you're asking for even more tuning woes if you do that. Run a mechanical advance with the BTM or one of the next generation timing controls (they can be better tailored for driveability, whereas the BTM is a 1-for-1 deal).

IRT what you want at 2200 light load, your BTM won't be in play, as you won't be on the boost. If you go to a digital ignition setup, you will be able to tailor your cruise tables. You don't want excessive advance, as this will cause all kinds of cruise rpm overheating issues, as well as lowered part-throttle response.