we know about the singapore VPN because they connected to IRC on libera chat with it. the only reason I can think people would believe they’re from hong kong is because of the pseudonym they used, but it’s not like that proves anything.
see link posted in another user’s reply: https://boehs.org/node/everything-i-know-about-the-xz-backdoor#irc
I don’t foresee anyone with the kind of data needed to do more investigation releasing it to the public, so I doubt we’re going to be getting any satisfying answers to this. Microsoft may have an internal team combing through github logs, but if they find anything they’re unlikely to be sharing it with anyone but law enforcement agencies.