With BFGMiner and set-device, you can specify either the device path or device serial number, e.g.
--set-device antminer@/dev/USB1:clock=ABC
--set-device antminer@S1234567:clock=XYZ
The issue with using the device path is it may change after a reboot. The problem with using the serial number is many hardware manufacturers still do not brand their devices.
However, you can use the following tool to fairly easily add serial numbers and branding to cp210x devices:
http://cp210x-program.sourceforge.net