Salute!
Adding to previous post....
1) About every plane I flew caused ther nose to go down when I lowered the flaps, even the T-33 which had split flaps and not the fancy ones I had in other jets. So looks to me that the pitcvhing moment was lowered when at the slow ( low q and mach) part of the envelope. The leading edge devices prolly also lower the pitching moment induced by those big motors way out in front and higher than the NG or previous.
2) At high mach use of MCAS, might be the new motor configuration introduces some shock wave phenomena, but not like that at low speed/high AoA. Hence the different amount of deflection.
3) The pitching moment comes from more than just the stab and or flaps. Adding new, big motors at a higher position and further forward can definitely affect the moments. So I show again an actual aircraft moment diagram that shows a positive pitch moment even with neutral stick at about 10°. And that was on the left side of our normal AoA during hard maneuvers. Scary, huh? Our problem was running outta nose down stab capability.
Gums sends....