the Max will raise the bike's rear geometry 0.47" and it actually corrects the speedometer's imprecise factory calibration, a deviation of about 7%, I believe, at least on older model R3s. The trouble caused by different tire sizes on R3s with ABS is caused by putting smaller than stock section width tires up front.
Surely others with more direct experience will come along and confirm or correct this, however the problems definitely occur with a 130 tire in front, I'm not certain about that with a 140 tire.
Also, make certain that you are not confusing the Exedra (usually a 'G' series tire) for the Exedra Max or a bias ply tire for a radial as I am unaware of this "new" Exedra Max model to which you refer. I believe that there has only been the one EM since it was introduced about two years ago.