Now that's just plain ridiculous!
There probably isn't a better time to do so. It is the ONLY way to find out what the judges think, and they are the only ones that matter.
Case in point, me!
I am not happy with my ribs. I think that they're good, but I am still not satisfied with them. The last three comps though we've finished 3rd, 1st and 1st in ribs!? The 1st contest where we finished 3rd, I sat there trying to decide which to turn in, and finally said, "Well I'm really not happy with these, but they're the best that we have, so we're turning them in." 3rd place call, so WTF do I know? Next two contests decided not to change a thing based on the previous 3rd place call, and still I was not happy with them. After two consecutive 1st place calls, I realize that it doesn't matter what I think.
Now my brisket is another story. I really like my brisket, but the judges have a greatly different opinion. Last competition, after turning in brisket, I said "This is without a doubt, the best brisket I have ever made! That means we probably tanked." Sure enough, we came in something like 42nd out of 45 teams. So at Williepallooza I am doing EVERYTHING different except that it will still be brisket. I'll let the judges tell me how it is. I know they can't be any harder on me, and I know that it doesn't matter what I think, so why not do something for the first time in competition?