Timing Question, Highway cruising Options

[Dr. Roger]

I have a mechanical and vacuum advance mallory distributor.

I understand that when highway cruising the throttle is slightly cracked and the rev's are at about 2500RPM's. (high vacuum state and moderate mechanical advanced timing) FYI, I have the flipped H gear and a V8.

In order to maximize mileage, power, and reduce chances of overheating due to retarded timing, shouldn't timing be advanced as much as possible?

Then, if the throttle is mashed down, the vacuum shoud retard quickly until RPM's increase ?

The reason I ask all of this is because i noted o a few racing websites they offer agressive advance curves. Now I interpret this as timing advancing more quickly but does this also allow more total timing? And isn't there a limit to total timing?

Thanks,
Roger