Combine the sugar, cornstarch, sweetener and orange rind, pressing out all the lumps. Dump the blueberries into a 6-cup shallow casserole that has been lightly sprayed with non-stick vegetable cooking spray. Dump the sugar mixture, add the lemon juice and toss well to mix. With a potato masher, lightly mash the blueberries, set aside. Butter the bread slices lightly on one side, stack the slices and cut into 1/2" cubes. Dump into the casserole and toss well to mix. Bake the pudding at 350 F for 30 minutes, remove from oven, add the evaporated milk and stir well to mix. Return to the 350 F oven, and bake for 15 minutes more, uncovered. Served warm, topped, if you desire, with a little whole milk.