I noticed that the current SYZYGY capable development boards and pods Opal Kelly offers have plated mounting holes with a few millimeters of copper surrounding them. I see that in the specification calls for mounting holes with 3.2mm inner diameter. Searching through the documentation I could not find specification whether the holes should be plated, how much copper should be surrounding, and, if there is plating/copper, should they be connected to a ground plane.
Are there any specifications for mounting hole plating/connection?