Personally I vote for 1mm thinner!

Although, I'm not sure if having bare magnets on the backside will attract random metal objects nearby. Every once in a while you'd have to brush staple pins and paperclips off your pocket

Possibly a stupid idea:


Use some crazy glue to hold the magnet in place. This way the magnet is closer to the other-other half and the wood covers the whole back side (thus distancing magnets from attracting paperclips).