You can actually apply $17,500 of the 529 Funds to your Mid/Cadet's expenses at the SA's.
You can also apply this amount to a cruise, a new car, or a trip to Disneyland. If your kids is a student at an academy, the Military Family Tax Relief Act releases all 529 funds back to you penalty-free minus taxes on the gains. It is now your money to do with as you wish. If you apply any of it toward your cadet/mid's expenses, it is the same as just paying out of your pocket. The tax act was implemented to spare military families the penalty on funds that can no longer be used for college as the academies technically don't qualify as 529 institutions.
There has been excellent advice shared here about keeping funds available until your student commissions, but those funds are no longer restricted college savings; the money is yours to do with as you wish.
(Of course, if you have multiple children, you may keep the funds in the 529 and use them as intended for civilian college.)