Well you mount the VHD, let's say the driveletter is X:
Run this from admin Comment Prompt to load the offline system registry
reg load HKLM\sys X:\Windows\system32\config\system
than use regedit.exe and check "Start" dword value, it should be 0
HKEY_LOCAL_MACHINE\sys\ControlSet***\services\iusb3hub
HKEY_LOCAL_MACHINE\sys\ControlSet***\services\iusb3xhc
and finally unload offline registry with:
reg unload HKLM\sys
or use WinNTSetup on the mounted VHD, check the native USB3 checkbox on Ready page.
BTW: If you don't select a source in WinNTSetup, but an installation drive with existing Windows Installation,
all tweaks and setting will be applied to the offline system.