I agree that fear of nicks is not a good enough reason to wait on the bottom finish. If you just plain don't want to do it now, that's fine, you're not the first, but if it's just nicks you're worried about, I'd go ahead. Esp if the bottom is going to be graphite/epoxy, which I happen to like.
I think Dan S did his bottom before the flip but not the sides, which may be a good compromise. It means you don't need to flip again, but the sides, which are most vulnerable, can be done later.