I don't know about the ellipse wheel, but redishing a wheel should be a last resort to fixing a minor error in chainline. A symmetrically dished wheel is always best, particularly for something with as few spokes as an Ellipse. Honestly, you are probably much better off using one of these...
http://www.ebikestop.com/Items/004-cr1239? ...to move your BB over 2.5mm.