It would be far simpler to just sight the rifle in to hit as far to the right as the scope is to the left- Then the targeting line of sight will be parallel with the bullet's flight path as far as one could wish to shoot (not considering wind).
Unless you can sight it in at the farthest distance the bullet can travel, it will never be truly parallel to the bore's centerline! You could sight it in at the maximum range you think you'll ever fire, but that will still make a slight difference at everything closer.
This will work great for hunting rifles, as accuracy is minute of deer. But an offset mount isn't a good choice for accurate target shooting.
