What I meant was that the accuracy impacts how much "pick up" you can get from a better theory.

Agreed. Because of the simplicity of Newcomb's proper, I think this is going to make for an unimpressive graph, though: the rewards are linear in Omega's accuracy P, so it should just be a simple piecewise function for the clever theory, diverging from the two-boxer at the low accuracy and eventually reaching the increase of $999,000 at P=1.