Here is a booklet-length paper on “Origin of Covid—Following the Clues", a long paper on Medium by Nicholas Wade, who writes for Nature and Science. The tagline is “Did People or Nature open the Pandora’s Box at Wuhan?”
Wade points out the conflicts of interest, at WHO and even in the US NIH, which deter totally honest I investigation of the work going on in Wuhan Institute.
Wade discusses furin cleavage, comparisons to earlier forms if SARS, and some statistical observations that lead to the idea that the lab has something to do with it.
Spike protein monomer, Wikipedia embed, click for attribution.
Update: May 10: Sky News has an interview with Wade.