That part of your analysis is not correct. Stability and pitch sensitivity are not the same thing. On a Canard moving the CG rearward will decrease pitch sensitivity, but it will also decrease stability. The canard wing must stall before the main wing. If the main wing stalls before the canard the airplane will be unflyable. Moving the CG back raises the loading on the main wing and decreases the loading on the canard, making the main wing more likely to stall first.

The recommended CG on the Rich Model Long EZ is about right if you balance it with the tank full. If you balance it with the tank empty you are already pushing the rear limit of stability. Move it back a little more and then pull a high G turn and you may no longer be in control of the airplane.

Jim