I think on any bow if you do enough testing you will find a place where a heavier arrow will fail to increase KE.
I just gave you 2 bow reports where extensive professional testing was done. Far more than you and bigbulls do on many more arrow weights and over a larger span of weights too. They didn't find that place! In every single measurement they show increasing ke as arrow weight increases. How do you explain that? Did you even bother to look at the reports?