This is already/still an option. What you're looking for is the "eye" icon at the top to show the DNI column. For Z-Wave devices, this will be the hex node ID.
But there's no reason to go to the Devices page; it's already right on the Z-Wave Details page, too, the ID starring with 0x and that is not inside parentheses (that one being the decimal ID). Maybe that's easier?
