http://www.yss-aya.com/cgos/19x19/bayes.html
black_hole_v7 in third place. I only found this https://www.reddit.com/r/baduk/comments ... ai_in_the/
is there anything else about this bot?

Yeah there have been some threads about it before in a few places, such as in some chatrooms. I don't think it's worth paying too much attention to. Fairly likely it is just some arbitrary individual either running one of the few strong Chinese bots or other privately-developed bots, or running a modified version of KataGo itself, on sufficient hardware to compensate the disadvantage of that opening. (And yes, the fact that a strong bot plays such an opening does not mean the opening is good - it is almost certainly just hardcoded. Keep in mind that even more a suboptimal opening, superhuman-level bots can give themselves or other bots full handicap stones and win if there is a hardware advantage).

I might guess they are doing it mostly for fun, or possibly to try to troll people who would pay a lot of attention to things like this into believing that the "black hole" opening is some uniquely mysterious powerful opening.

I think on CGOS you cant set handicap games, so maybe someone is checking strenght of some AI with black hole opening as a handicap?