Just for giggles, I curve fitted the EGT and Valve temperatures using third order polynomials.
Turns out the peak EGT is at a F/A ratio of 0.0649, which allowing for various uncertainties explains how Lycoming nominate the figure of 0.0648 as the F/A ratio peak EGT in their "Power from Fuel Flow" document.
I thought it was interesting.
I will bow out and let the belligerents continue to argue past each other.