I'll check out your article after a bit, but for the time being, Earth circumference.
Is the circumference based upon an average of land height which includes mountains and ocean-trenches?
Is it based upon water level across all the oceans and seas?
Is it based upon an average between land and water level?
Would there be a difference in ancient estimations of circumference due to ice-age trapping causing water level to be lower making land height higher?
Would that make formulas define a different RC and better math throughout your work and the work of others?