Crankbrothers Shoe Shields are essentially just that: stainless steel plates that are added in between the cleat and shoe to protect the soles from damage. The precision cut guarantees a fit that is far better than what you can do with tin snips and a beer can on even your best day and clever cutouts still allow the cleats to dig into the shoe as usual to prevent unwanted twist.
Shoe Shields are thick enough to hold up well over time yet thin enough that they add virtually no stack height to mess with platform stability and use standard-length hardware. The slick finish even makes for smoother rotational float, too. Your shoes will thank you.