I feel like this is all about your own priorities, but to me, if you can hit the same numbers at 275 that you can at 308, it makes zero sense to compete at the higher class. Hitting bigger numbers at a lower weight class is better, period. What you're saying here is that the 308 lifters who have competed in your state are weaker than the 275 lifters. Which means you want to set a record in a weaker class. I can't appreciate that mentality.
That being said, my approach would still be to add as much strength as possible over the next few weeks (not enough time to do much), and not even worry about your bodyweight until a few days before the meet. A water cut from as much as 290 to 275 would be the easiest thing in the world to do. Helll, I've cut 15 lbs in the 181 class, so that cut should be cake. Worst case scenario would be missing the cut and setting the records at 308. Seems like a win either way.
Best of luck at your meet, btw.