It works! Thank you so much. At first of course I could not help tinkering and went and enabled USB and then forgot about that, after which it carried on hanging on the ArcaOS logo. When I remembered I'd done that, I disabled USB and the installation went through without a hitch.
One change I did make was to set the upscaling to linear (form nearest neighbour) - this dramatically improved the font rendering.
Mouse movement is a little laggy/floaty at times, but overall, happy days!
Thank you once again.