That makes sense, thanks.

With regards to abiogenesis, that is a wonderful area for wild speculation. I say that having done a tiny bit of that myself :)

Certainly it would be helpful to have small-molecule catalysts to bootstrap life into having polymer catalysts.

I just do not think it matters much about excluding metals, since there were bound to be sufficient dissolved metal ions floating around. Of course, whether they were the 'right' metals and in a suitable oxidation state and so on is a different question.