There are a number of questions (mystery footage) regarding their US releases that might never get answered unless we contact the people involved. Is anyone affiliated with/know people from Xenon (I think they did most if not all of the Wu Tang labels). Is there any connection between Xenon and Ground-Zero?

I don't think Xenon is around any more. Last I heard (this was about 10 years ago) they were facing multiple lawsuits, even from Tai Seng - which shows you how shady the product they produced was.

George Tan (Bruce Lee "historian"/alleged bootlegger) was involved with Xenon on some of their titles. You could maybe trying Googling and seeing if there is some sort of email address for him out there.

Not sure if there is any relationship between Xenon and Ground Zero.