Why not just have a fully adjustable spacer setup in the rear, seat pads of different heights and widths, and allow the front forks to be raised through the tripple clamps, and have an option of spring rates...easy. Much cheaper than different frames and also easily tooled for I reckon on the popular models. Then they can have a "RR" version for the serious racers amoungst us.
Problem is most bike workshops won't do an individual setup for each person, it is left for the new bike owner to do that.