Another question, can we include your driver inside the script?
I don't known how LiveXP scripts work. I can't help in creating it.
Don't worry too much about the message in device manager that firadisk have no driver installed. It does not affect its operation. But if you can find the right registry settings, it would look good to users.
I learned about CriticalDeviceDatabase after I read Emanuel Schleussinger's article and Dietmar's thread about USB booting.
Usually when you add a new plug-and-play device to computer, the device do not have driver and cannot work.
However, if you have devices' HardwareID or CompatibleID in CriticalDeviceDatabase (or HardwareIdsDatabase),
Windows will use service specified by service value in this key to drive the device temporarily until it have a driver installed.
Legacy device detected by a driver (for example, detected\firadisk) use that driver to function temporarily until a driver is installed for that device.
If Windows find a matching driver signed by a trusted publisher, it install a driver automatically.
The device is removed from temporary driver and add to newly installed driver immediately.
If Windows cannot find a trusted driver, it asks user to install driver for the device.
The temporary driver continue to drive the device until a matching driver is installed or computer shutdown.
It seems Windows setup during txtsetup pass and PE don't ask user to install driver.
It just use (driver from database) or (the driver which report detected device) until reboot.