Sadly this feature is NOT a true pattern search. It doesn’t actually search for the board position that is displayed. Currently it only searches if the end positions have those stones present. This makes it useless for studying fuseki/joseki patterns.
Sensei’s Library has an excellent search feature, which includes the following
*Black stones
*White stones
*Empty space
*Unknown
*A stone of either color
*Black stone or empty
*White stone or empty
This allows for far more sophisticated position searches. Would it be difficult to replicate this here?