Thanks for your reply but... neither of these scenarios apply, because it's 2 longhaul trips that get you over 30K, not ONE, I corrected my mistake in the original post.

But based on how inflexible MPC appear to be on date resettlements after looking at your response, guess I'll just have to go for the hard way and see if I'll get more flying in between my mileage accrual period. I'm a GR aiming a shot at SL.