Hello, after digging a little more, I can't recognize a GL646 from the usbsnoop log. When looking at the 3000f driver, it looks really close to the 3200f. I think it is the way that should be explored. The USB descriptor is really close, the PID of the 3200f is the one following the 3000f. Driver wise, they are also really close. One interesting hint would be finding if it loads a firmware or not. You may record USB activity with usb snoop of the unplugging/replugging (with also powering it off) of your scanner. If there are some big bulk out write, this should be a firmware download.
Regards, Stef