USB Storage Device Drive Letters (U:) conflict with Network Drive Mappings

It appears that any USB storage devices in the Win10XPE system will get drive letters starting at U:.  This conflicts with our Network Drive mappings when logging in to the network.

I have already turned off the "CDUSB.y" drive and any system with a USB CD Drive now simply gets the next available drive letter from the beginning of the alphabet.  (This is fine for us as I have already developed a tool which locates the CD physical drive letter which I used in prior projects - i.e. Win8.1SE)

Anyway, does anyone have any suggestions how I might just let the system add drive letters for USB storage devices starting with the first unused drive letter (earlier in the alphabet) rather than U:?

another strange issue as drive mapping usually follows the Host drive mapping (thus starting with C)

We've spent a good deal diagnosing this and Win10XPE appears to always be "involved".  The old Win8.1SE environment doesn't do it and it doesn't matter whether we load Win10XPE from disc or via PXE...

It should also be noted that this might only be manifesting itself on certain systems.  The platform we are working with right now is Intel X299 based.  We are getting drive letters (U: and beyond) assigned on our hotswap usb/sata bridges holding hard drives...