Yes, the lowered riding position WILL allow a faster cruising speed, because the drag is reduced, and so the load on the engine is reduced. That will allow you to go faster at the same hp output, and you can increase the cruising speed that way, to the extent that the drag is reduced.
And that, in conjunction with a bigger sprocket can give you the lower rpms, and the reduced load on the engine, allowing a somewhat higher cruising speed, which will suit the desired goal.