The matching process will always be slower in interrogation than in Runtime because of the overhead of drawing the matching in the UI (and whatever else Studio has to display). Adding more controls will decrease the speed with which all of the controls match. Think about it this way; if matching is like a valet returning you multiple cars from a garage, the more cars that you ask her to return to you, the longer that is going to take. The specific match rules you use can also affect the speed. Try to use specific ones like IDs and Names or other inherent attributes of a control. Text and/or RegeEx are slower. Things like Path seem slowest in interrogation mode at least. Control Child MRs are the slowest.