You don't know if they ESD protection or not. There are loads of tiny little ESD protection ICs/diodes that can handle many inputs. Just put them very close t

You don't know if they ESD protection or not. There are loads of tiny little ESD protection ICs/diodes that can handle many inputs. Just put them very close to the connectors and you should be good to go from an ESD perspective. You don't need a metal shield around everything to protect against ESD. Every USB device connected to your PC right now probably has a little ESD protection IC in it. Usually sitting right next to the USB connector (as close as possible).