In increasing the right or down thrust of my engine, I normally do not offset the engine mount to align the center of the drive washer to the plane's thrust line. Some types of engine mount, e.g. GP adjustable mount, allow me to offset a little, but most of the time I just don't bother. I have a profile plane where the spinner offset is about 1/4", and it flies well. I've seen 3D planes with huge offsets and they fly well. My question is : Is it really worth the trouble to offset the engine mount to align the thrust line ? How will the flight trimming be affected ? Thanks