You and I are basically on the same page, but I'm a firm believer in using different gauges on right and left flanges of high dish wheels. In this regard it's the center section which is most of the length of the spoke that counts. That allows more equal strain (%elongation) of all the spokes despite the tension being lower on the left. The Op should decide on the right flange spokes first, then look for a lighter butted spoke for the left, though like you I won't go below 2.0 at the hub.