Players are able to walk into another player's protection field and use LWC to "/cprivate" a chest that they do not own. Basically they can walk into someone's field and "steal" chests that aren't already protected with LWC.

This would be something the LWC authors would have to check for using the PS api. They would effectively have to do this in their code:

boolean playerCannotClaimChest = PreciousStones.API().flagAppliesToPlayer(player, FieldFlag.PREVENT_DESTROY, locationOfChest);

The author of LWC replied with this:

"Any plugin can hook into LWC really easily since it has internal events (protection create, destroy, etc)."

Ok perfect, I'll add it when I have a chance.