You're not saying it, but you're obviously starting with a very different bayseian prior than my 50/50.

As someone that makes forecasts for a living, I'd like to see what you're assumptions are about the base rates there.

As for how the facts produce modifications to the base rate, personally I think that a virus identified in a cave over a thousand miles away popping up in a very urban area right next to a BSL facility that specializes in researching that type of virus moves the needle toward it being more likely a lab escape. You seem to feel otherwise and I don't really agree. In particular, if you take the converse: suppose the virus wasn't known at all to man, you'd probably argue it also pushes you toward the conclusion that it was a natural spillover. (In which case, I'd be in agreement.) So I don't think that argument is really a logical one.

Your objection in the last paragraph, describing this as a "bioweapon modified virus" is really a classic strawman, and since it isn't the argument I was making I see no reason to indulge it. It is indeed a relatively ridiculous notion.

Also, just for precision, my own assessment of the truth value there is about 70% in favor of a lab-leak.