Very often I'll see time and sales below my hidden bid at other exchanges than where my smart routed hidden bid is. Very often I'll get instant fills by splitting up my hidden bid and manually routing it to various exchanges that smart routing skipped. Their smart routing system should automatically handle searching for hidden liquidity at better prices than my bid. It should at least automatically do the obvious thing of routing parts of my hidden limit order to each of the few exchanges that have recent sales, since there isn't really any volume discount between 200 shares and 10,000 shares on my end.
Highly likely because the topic is posted in the forum section called "Company Specific - Interactive Brokers". Just saying ...