> The conclusion that life arose twice requires you to buy that proto-cells that grew on these vents and needed those metallic surfaces to survive didn’t count as “life”.
Well, sure. For it to ever be possible to say "life arose more than once," one must decide where the boundary between life and non-life is. After all, every precursor of life arose all at once, in the Big Bang!
Hardly. There are nucleic and amino acids pretty much in every star system, we now know. But not during the big bang. Theres a lot of intermediate stages before stars are young enough to have the mix of chemicals to give rise to these precursor chemicals to life.
Its stages, but it’s a bit hard to say “early stage was a single origin, then we count each bifurcated radiation as a separate start point”. Why not call it convergent evolution, which it would be, over a very long time period?