I'm thinking the same way as you. I've done this only a few times and have had no problems earning the booking bonuses.
I was concerned that somehow this might affect my upgrade chances. I'm not sure how they allocate MVPG/MVP upgrades when there are more elites than seats (fare class, price paid, when purchased, etc.).
I probably book about a dozen roundtrips per year, so that's an additional 12K in miles.