I don't know whether this happens for anyone else - my Simplify3D is configured for a Makerbot 2X and has a left and right extruder. However in the extruder tab, it always loads up the left extruder regardless of the "default" extruder auto-configured (eg "Right Extruder only"). It'd be useful if the Extruder tab were to load up the configured extruder - personally I have forgotten many times (assuming it'll load up the extruder I've got configured) and have accidentally changed the settings for the wrong extruder.