Go to home depot and use an industrial lightswitch plate. They're less than a buck and just sturdy enough to hold your cleats in while giving you the needed surface area.
My friend and I did this, a long time ago, like 1995 ago. Once you get it done you have a foot interface that's a culmination of the worst features of clipless and platform pedals combined, and none of their benefits. It sucks but it's doable.