Was Boeing just putting 777 type design into the 737 MAX? And if the 777x engines are larger & placed higher & more forward than the prior 777s, does 777x have even less "longitudinal stability" ?

https://www.boeing.com/commercial/ae...y/fo01txt.html

2 Flight Control Computers and Stability Augmentation
The trend in the design of modern airplanes is to have less static longitudinal stability--frequently referred to as relaxed static stability (RSS)--to capture the benefit of improved fuel efficiency. Simply stated, some airplanes are now designed to be aerodynamically efficient, and stability is augmented electronically so that stick force gradients will meet certification requirements. Many methods exist for augmenting stability. For example, the Boeing 777 and MD-11 use flight control computers that adjust the elevator actuator positions to give the appearance of more longitudinal stability than the airplane actually has. In other words, computers absorb the extra workload caused by flying with RSS.

Augmented stability provides better cruise performance with no increase in workload and no adverse effects from flying at an aft CG. This technology also allows for a smaller tail size, which further reduces drag and weight. However, FAR Part 25 requires that handling qualities remain adequate for continued safe flight and landing following an augmentation system failure. Therefore, a practical limit exists for how far aft the CG can go.

The Boeing 777 uses redundant digital flight control computers to provide positive (static longitudinal) stability and enhances that stability with airspeed feedback. The MD-11 uses computers to provide neutral speed stability. In other words, the CG of the MD-11 appears to be at the neutral point. The MD-11 uses elevator deflection to hold attitude at any speed within the normal flight envelope, then trims the stabilizer. This is known as an "attitude hold" system.