"Let’s look at the big picture: A novel SARS coronavirus emerges in Wuhan with a novel cleavage site in it. We now have evidence that, in early 2018, they had pitched inserting novel cleavage sites into novel SARS-related viruses in their lab,” said Chan. “This definitely tips the scales for me. And I think it should do that for many other scientists too.”
Richard Ebright, a molecular biologist at Rutgers University who has espoused the possibility that SARS-CoV-2 may have originated in a lab, agreed. “The relevance of this is that SARS Cov-2, the pandemic virus, is the only virus in its entire genus of SARS-related coronaviruses that contains a fully functional cleavage site at the S1, S2 junction,” said Ebright, referring to the place where two subunits of the spike protein meet. “And here is a proposal from the beginning of 2018, proposing explicitly to engineer that sequence at that position in chimeric lab-generated coronaviruses."
And then what's more, they sat on the fact that they had requested funding for this research for the last 18 months, when the world has been desperately trying to find any relevant information on the virus' origins. The fact that they did not put this forward themselves in in and of itself suspect.
What you're saying is worth looking deeper into, but it's not enough to start making claims yet, imo. There are probably hundreds or thousands of proposals and papers floating around now that talk about different things one can do with genetic engineering. If something should arise that is related to the concepts in some of those papers you wouldn't necessarily jump to the conclusion that there's a causal connection. Not without more information, anyway.
"it is the aspect of the genome which is hardest to square with a natural origin" This doesn't tell me it's artificially created. The most this tells me is it's not well understood.
"The fact that they did not put this forward themselves in in and of itself suspect." It could be related. Or it could be unrelated and there maybe some other explanation. My point is, when you want to charge someone with a serious crime, which I think this falls under, you need to come with some pretty strong evidence that directly ties whoever is involved to the events of the crime. This evidence may very well exist and it's not been shared publicly.