Going back to the statement about being a smidgeon thicker being better, that's correct.

The aft portion of a wing experiences a lot of turbulent air and airflow separation, so having a flight surface that's about a mm taller than the trailing edge of the wing where the moving surface joins it helps to keep the surface in "good" air, and keeps the flight surface more effective at higher angles of attack. Of course there's that point where the only airflow over the moving surface will be at the inboard section and is generated by the propeller only, but until that point and angle of attack is reached the thicker moving surface remains effective longer.

A centimeter is of course waaay too much.