USBs visible on Rekordbox Export Mode to CDJs over Pro-DJ Link?

If I have a computer running Rekordbox, that is in Export mode and providing its Collection over Pro-DJ link to a set of CDJs on Ethernet, will the CDJ formatted USBs that are plugged into the computer have their contents available over Pro-DJ link to the CDJs? Or do the USBs need to be imported into the rekordbox collection first?

Basically we have a show where 6 DJs will be performing a fast-mixing B2B on a pair of CDJ-3000's, one song each in rotation, and all need quick access to their libraries (especially if it turns out when we show up to the venue that one of the USB ports is damaged). We're trying to figure out the method to most quickly enable the DJs who show up to plug in and go.