I'm curious.
How do you know the RPM where reversion stops and the cylinder volume captured approaches 100%? It would be different in 2 engines with the same cam, same head, and same CR if the rod ratio were different.
The hot spot that is frequently the cause of knocking is the closest to the plug and/or exhaust valve. How do you know how hot that is since it follows load as well as water jacket temperature?
I'm certain that these are relevant factor, but do their ranges contribute so little to the calculation that the results are still useful?