Mandatory Slide Rule

I've always had one problem with the mandatory slide rule in that many catchers are taught to take advantage by stationing themselves 3-5 feet up the third base line thereby denying a sliding runner any opportunity to reach home. Major league catchers pay a price for this strategy! Even throws up the line cause umpires problems. Anyone agree and suggest a solution? By the way, I stumbled upon this page as I'm preparing for our AABC 10 year old traveling season here in Lake Villa, IL. Great Stuff!