When a power setting table shows a "best economy" and "best power" setting
for a given power level (say 75%) using a given MP and RPM this is just a
starting point, right?

Once the MP and RPM has been set and the leaning done, the actual power
settings would be more like 78% for best power, and 73% for best economy,
wouldn't they? (%'s are just guesses, no science involved).

Thanks in advance.