Actually the impact would be greater the further out it goes, regardless of where the center of lift is. From that perspective, ignoring all other consequences, you would want to move the engines out to the wingtips.

A 2% improvement on a plane of any type is a huge improvement. I would assume that that wouldn’t be enough for a design this different looking to be approved so there must be other benefits of the design, but a 2% impact in practice is a big difference.

Also, an aero engineer. there likely would be some structural savings putting them on the wings. Helps with the moment put on the wings during flight. Same reason we try to put as much of the fuel in the wing tanks as possible. Having the engines mounted this close to the fuselage might make that less pronounced, but…

the more mass you have on the wings, the less the turbulence will affect it. it’s based on the amount of momentum required to move it