I agree end-stage attendance shouldn't be compared with in-the-round, which is why I focused more on Play On and Blown Away sales figures. Though I'm not sure why you would scale down within a venue (i.e. reduce seat availability) if you've already committed to touring that arena—besides more easily achieving a "sell-out." I can't imagine there are significant, or any, variable costs from having 10,000 seats available compared to 8,000.
Interestingly, Carrie sold 9,979 seats (of 12,286 available) for D&R at the Rupp Arena in Lexington which is actually more than the 8,267/8,534 sold for Play On at the same venue. So who knows, not enough data on D&R's box-office yet to tell how it compares to past tours.