Why am I qualified to comment? Well, I’m a medical doctor (which frankly means jack shit for the ability to parse this paper) but got there through a major in biochemistry and molecular biology (which is a partial toolkit).
Unlike their paper on Biovacc-19 (0) it has not been accepted or submitted for publication yet (not enough to rule it out immediately because there is an increasing trend to pre-publication with the rate of research publications in this space as well as problems with traditional publication methodologies)
Without going too far the dissection, I would just point out that the overwhelming scientific consensus is that SARS-CoV-2 is natural in origin, this nature article describes this well (1).
Worth specifically responding to is their claim that
The co-receptor dependent phagocytic general method of action for infectivity and pathogenicity of SARS-CoV-2 appears to be specifically related to cumulative charge resulting from inserts placed on the surface of the Spike receptor binding domain, right next to the receptor binding motif.
Inserts placed is a poor choice of descriptor in my opinion. The Fox Newsification of research findings. Well, you can see the 4 additional amino acids that give rise to the change in isoelectric point in the spike protein in the nature article, and much greater minds than mine have dissected this genetically and decided that such a mutation is possible through evolutionary methods alone.
They specifically say they disagree with the findings of the nature paper so to go on any longer risks drawing my bow in this area further than I am comfortable, but I would sum it up by saying that in science it is always good to have dissenting voices (such as with climate science for all the good that that does), but with just how fraught the world stage is at the moment I don't believe this dissenting voice deserves much attenion
[0] https://www.cambridge.org/core/services/aop-cambridge-core/c... [1] https://www.nature.com/articles/s41591-020-0820-9