10+ isn't GF so might have to stop short of game. 10+ is unlimited so must be forcing. So some of your possible contracts are 3M, 3N and 4M. So, you have used up all out of space and no closer to knowing what the final contract is. Worse the right contract could be 3S, so might only have one more bid. A jump to be useful needs at least to be GF or limited.