Hope you realize best execution does not mean an exhaustive search. Per NASD Rule 2320, a broker only needs to contact and obtain quotes from three other broker-dealers (or all if there's three or less) for a stock trading on the grey market.
Whether someone's order sits, is partially filled, or is fully filled depends on which three broker-dealers are contacted, the time, and how frequent your broker checks back. If you guys complain enough, TDA could put CKYS on a restriction list where they won't fill any buy orders.
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"We simply attempt to be fearful when others are greedy and to be greedy only when others are fearful."
-- Warren Buffett