OK-
It is a logic question.
If the plane still weighs the same -the total lift must --remain the same - so wing loading is --the same
If shoving the cg forward -eventually slows the plane from level constant flight - then something else is at play - in this case the forces necessary to hold the wing at best AOA for best speed with least power consumed are increasing.
Those forces are -the tailplane force which stabilizes the AOA and the powerplant thrust (inc direction of thrust)
To me , this is a more simple view of what is at play.
If the stabilizing piece (stabilizer?) operates with less drag - less energy is consumed in holding the plane level
You could call it accumulative lift or whatever -but isn't that is what is happening?
again, the only formulas I am really up on, are baby formulas