Will verify next week when I get the real hardware next week (or whenever it arrives)

so an entry in txtsetup.sif shouldn't be required 

They will still need to be present in the I386 folder of XP source though, to prevent "File not found" errors with XP textmode install.

Once again: why do you like to add VIA USB3 drivers?

Do you like to boot from a internal CD drive.
And load VIA USB3 drivers gui mode PNP?

Do you like to install XP from a device attached to a VIA USB3 controller?
What about textmode part? Do you get a BSOD 0x7b that way?
What about first reboot, reading files from a device attached to a VIA USB3 controller?
That's before gui mode PNP driver loading.

Verify this at real VIA USB3 hardware.

I tested it out, it seems when the driver installs it copies wdfldr/wdf01000.sys to system32\drivers automatically,

so an entry in txtsetup.sif shouldn't be required (if it is not in txtsetup.sif it also means that these files won't be copied onto systems with no Fresco/VIA hardware)

They will still need to be present in the I386 folder of XP source though, to prevent "File not found" errors with XP textmode install.

I wanted to test run the VIA USB 3.0 driver INF in my VM

Do you use a USB 2 and a USB 3 controller at VMware?

Edit VIA xhcdrv.inf

Be aware:
the driver xhcdrv.sys will fail to load at fake hardware

I wanted to test run the VIA USB 3.0 driver INF in my VM, but it won't let me run it.

or is there a way to force it to run without the hardware being present?