The maximum "rate of flap up" i.e. the vertical speed is reached at the end of upward cyclic component of the aerodynamic force that is controlled by the AoA, not at its peak.
If you mean that the journey around the swashplate can be considered as half uphill and half downhill with two 'neutral' positions in the middle, then from one neutral position, the blades start moving up and reach the maximum rate of flap up 90 degrees later but the high point of travel 90 degrees after that - then I agree with you but I don't think that is what you are saying.
The difference between those of us who are helicopter pilots and those who are theorists is that we get paid to do some of exciting stuff mentioned already on these pages, using our training and skills to complete demanding tasks in the machine we are given. As a result, most of use give little thought or worry as to whether the rotor is flapping or precessing (it is flapping btw) so much of your well-intentioned analysis is irrelevant beyond academia.
But don't take it to heart, keep on arguing your case - someone, somewhere cares.