Changing the timing doesn't change the power of these motors much if at all. All it does is change what gear you need to run.
More timing = smaller pinion and less timing = larger pinion. So, if you don't want to "tweak" on your motor just set the timing (to any point) and forget that it's even there.
For what it's worth, I'm finding that in 4 cell 12th it's better to run less timing and more gear because it tends to keep the speedo cooler. Don't know why, it just does for me.