I've talked with all the hosts and the TDs and we've decided to go with BW2 for the entirety of the Grand Slam. BW2 is available in all tiers on both PS! and PO, so players have a means of practicing and building teams. I know it's a little rushed for the UU Open, but by the time the other four tournaments start and the UU Open gets going, we'll be definitely very well entrenched in BW2. If tier shifts occur during a round, they will be taken into account in the subsequent round.