No - at least for me that's not the reason why I do what tom911 suggests. I just feel that if other passengers' boarding groups have been called, we're in the same position: entitled to board. I don't feel right jumping in front of other people once they've been called to board, and I think it raises people's blood pressure when they see it done. So I don't do it, even though official policy says I could. Nothing to do with whether the agent knows the policy.