I call your "research" into question since you seem to have come to several conclusions which are completely incorrect. You are correct that two Kelloggs experimented with grains including wheat before trying maize. You are incorrect when you say that "corn flakes" were ever made of anything but maize. In America, "corn" never means wheat or any grain other than maize. The original flakes of wheat were called "granose."
You are also incorrect when you say that it was a non-Kellogg who added sugar. In fact, corn flakes were originally marketed by Will Keith Kellogg's Battle Creek Toasted Corn Flake Company and contained added sugar from the beginning.
Will's brother John Harvey Kellogg, who was not part of the business, was not in favor of adding sugar. John's objection to adding sugar had little to do with modern ideas. He thought spicy or sweet foods would increase sexual urges.