Thanks for the reply.
It's basically trying to solve a 2, 3, or 4+ variable function without enough data. You can guess and solve it in one circumstance, only to have it be off in another.
Murfie, that makes sense. I was thinking about it somewhat differently. By locking into specific MPs and logging, you may get into an operating condition (load/rpm) that you normally wouldn't see in that MP alone. But that's okay. The MP is most importantly defining cam angles, which probably have the biggest affect on the rpm/load/MAP relationship you are trying to tune.