I think for small donors, donating to the best unregistered charity is >>2x times the best registered charity, for the reasons OP outlines: registered charities are much better covered by large institutions, and lots of people are overanchored on registration so the unregistered are neglected by comparison.
The counterargument is that bednets/givedirectly are just pretty good and it’s unlikely any particular new thing beats them. Which is a fine approach, but not what we’re talking about here.
What effects did you have from what dose of glycine, and how quickly did they kick in?