It has since been generally agreed that the XV-1s performs best at around 2.1g VTF. However, it might be worth trying it with a slightly greater weight until it is broken in. SO far, I have found the best tonearm match to be with an Ikeda IT407 with a light weight (very cheap) Altai headshell and set up with the Feikert protractor. From my experience, the improvement in sound from usuing the protractor and disregarding the manufacturer's instructions if phenomenal.
I am as close to reality/live performances as I have ever been with any analogue set up. I know that Raul has had a great experience using his XV-1 with an Audiocraft AT3300 and hope to try this out at some future point. For now, setting the XV-1s/Ikeda/Altai combination up using Dr. Feickert's protractor at 2.1g VTF is a recommendation I can honestly make.
I hope this helps