Youth Football Audibles

I found a post at Youth Football Drills explaining how to use an audible system in youth football. It has me thinking how I can tweak my system to include calling an audible at the line of scrimmage based on what the quarterback sees on a presnap read. I can see potential for having the quarterback read the defenses reaction to our Over and Under unbalanced formations and having a play to take advantage of either no reaction or an over reaction.