Open houses scheduled for after "final and best" deadline

[Jane Hudson]

QQ - I'm bidding on a property and have been told there is another offer. The listing agent sent me a "highest and best" deadline which I responded to. About the same time I submitted my offer, they scheduled 3 open houses for after the deadline. Was their deadline just to try get a baseline offer to use as bait at the open houses? Should I withdraw my offer or put a deadline on it so it expires before or shortly after the open houses?

Related question: do buyers ever submit comps with their offer? The seller's agent sent me their comps, which I respectfully disagree with.

Thanks all!