I assume by "dual ailerons" you actually mean dual servos. Or do you really mean you want to add extra ailerons?
As for dual servos, I haven't done it to an MKII, but I have to a couple other planes including the Avistar and Tower .40. It was really a waste of time on both. I may have gained a little roll rate on the Avistar, but this was probably due more to the semi-symetric wing foil. The MKII is a flat bottom wing like the Tower .40, so I don't think you would gain anything unless you are planning to enlarge the ailerons. On both of the planes I mentioned, I located a space between two wing ribs near inboard end of the aileron and constructed a servo mount which i glued to the wing ribs. I also reinforced the opposite side of the closest rib to stiffen it up.