These planes are designed with fuel economy in mind and in cruise get trimmed for rearward CG for better economy and at cruise they are also flying close to coffin corner. The automation can fly the plane to the accuracy needed in cruise but can a low hour pilot flying manually?
In smooth air the PF would probably not need to touch the side stick for a minute or so until the UAS corrected itself, but in turbulent air, at night, and possibly in cloud that is a difficult scenario. I think the autopilot dropping out and control laws degrading so protections such as stall protection are lost, should not have to be the case for a UAS. Design a system for the worst scenarios and build in redundancies to better give the pilots a chance to manage that system when there are failures.