1) Be content with the 30-second auto-sync like everyone else.
It's not clear to me that the 30-second auto-sync is reliable, either. I can't find it right now, but I read an ACM paper a few years ago that compared several filesystems and showed that they had widely varying behavior with respect to unplanned shutdown. Varying the hardware makes reliable behavior even less likely. I don't think waiting thirty seconds will fix that.