Lessons will have been learnt, for sure, but clinical trial design is always a matter of balancing science against the costs, which in turn are dependent on things like the duration of follow-up, the assumptions built into the power calculations that determine the sample size, selection crieria, and so on. It's always a compromise and a question of making the best decisions within budget constraints. 
It's easy to be wise after the event, of course, and this time they will have the help of the FDA, but I think the more money and experience that goes into BoM2 the more likely is it to give a clear outcome, and imo that means bringing a BP on board.