Actually the sidesaddle mount (cylinderhead 90 to the right) as far as engine function goes is the best possible position. this allows positioning the tank in the best position for the most uniform engine run throughout the run with the tank centered on the spraybar. Its for this reason virtually all pylon racing airplanes are sidesaddle designs. Another very good reason for this is safety. This mounting will put conventional needles straight up and a much better position for adjusting.

Concerning vertical and lateral thrustline changes, both will affect flight slightly with vertical changes actually effecting a more obvious change than a lateral change. All airplanes have a vertical CG as well as a longtitudinal one this is the point where the lateral axis runs through the airplane. If the thrust line is below that point (as most high wing cabin types are) then when power is increased the ship pitchs up and down when reduced. Down thrust is designed in to combat these pitch changes with power changes but this only occurs at one power setting.
Raising the thrustline can reduce these pitch changes or lowering it can aggravate it. In the case of low or mid wing aerobatic type there is no or very little pitch change with power because the thrustline is very close to that vertical CG if you will or lateral axis.

Lateral thrustline changes. Most high wing types have right thrust designed in to combat the left yawing tendency at low airpeeds and high deck angle caused by among other things 'P' factor which is a disymetry of thrust across the propellor as a result of that high deck angle. Now moving that thrust line to the left (not changing the angle ) will have a slight effect of increasing the right thrust and moving the whole thrustline laterally to the right without changing the angle will have the effect of reducing the right thrust. These lateral displacements of the thrustline (not thrust angle changes) has only a marginal effect because of the confines of the nose.

Sorry for motor mouthing

John