2. There is no spike protein anyone knows of which would have been used in this research
3. The PRRAR furin cleavage site is not one humans would have tried it is unlike any other known furin cleavage sites in coronaviruses
4. There are now many known related sarbecoviruses which have been found with furin cleavage sites
5. Furin cleavage sites have independently evolved in multiple different branches of coronaviruses, probably a dozen times that we know of now.
6. The furin cleavage site is short and can easily happen through recombination with another virus due to coinfection.
7. This is very likely what happened due to infection with the SARS-CoV-2 ancestor and an HKU9-like virus.
It is not particularly suspicious that the thing which we were worried about happening and causing a zoonotic spillover event is the thing which actually happened.
They were going to experiment with multiple backbones, experimenting with multiple variations of spikes, looking specifically to try novel types of furin cleavage sites.
There was no public reporting of what happened with this research. We don't know what they have because WIV database was taken offline. They claimed to have searched it, but what they claimed was the closest match in the database was not, in fact, as close as a sequence they had published. Given that demonstrable lie, there is no way to verify any claim about what sequences were or were not known and possibly involved in this research.
Furthermore the person who submitted the proposal was also the person who broke ethical standards to preemptively shut down all discussion of a human release.
That isn't to take away from the possibility of a natural spillover. The facts that you say about that are facts. But accidental release is also possible. And the lack of transparency from those who are most likely to have made the mistake heightens suspicions, it does not lessen them.
It is research that "sounds like" what happened with the SARS-CoV-2 zoonotic spillover, but that isn't a strange coincidence. They were researching the thing they were worried about happening, and then it happened. Their research proposals naturally rhyme with what actually occurred because they had studied and understood the problem enough to guess more or less accurately what the process would be. There are still massive gaps in between this proposal and SARS-CoV-2 that you could fly a plane through.
It's like seeing smoke billowing out of a building and refusing to accept that there's a fire until you see the flames. Very convenient that your standard of evidence surpasses anything we can possibly obtain after the CCP scrubbed everything.
Why? The wet markets in Wuhan were sterilized and emptied (meaning that the animals inside were removed, killed, and their carcasses disposed of) at the very start of the outbreak - several days before anyone had definitive evidence that SARS-CoV-2 could be transmitted by person to person contact.
I'm sure that the Chinese government would love to have definitive evidence that SARS-CoV-2 is zoonotic, but that evidence likely went up in smoke (January 1st, 2020) weeks before anyone realized that COVID-19 would turn into a legitimate pandemic (January 23rd, 2020).
This is why there has been a lot of attention on certain animals, such as raccoon dogs and minks. It turns out that a lot of the early infections linked to the various Wuhan markets were from shop owners and employees who either sold or were in close contact a small number of animal species. It also turns out that these animals can be infected by SARS-CoV-2. See https://ncrc.jhsph.edu/research/animal-sales-from-wuhan-wet-....
The issue is that (as far as I'm aware) there's no immediate evidence that SARS-CoV-2 jumped to humans from any of these animals, only that there was an (again, as far as I'm aware) unknown intermediary species. However, because the animals at the wet market were disposed of, there's no way to definitively link SARS-CoV-2 to them.