I'm using the lr32 system to put holes for Pro 200 full extension drawer rails in a shop cabinet. The front hole is at 37mm from the front edge which was easy. The back hole on the rail is 197 mm from the front edge which happens to be about the mid point of the board (~400mm). Is there a particular trick for using the side stops to go that far or do I need to just measure out the spacing manually and clamp my rail as even as I can do? (carpenter square/etc)