In the often quoted Altman and Henn paper, Photo Sci Eng: 5 129, 1961, they looked at variants on the D23 formula the highest acutance was with AH15.

Metol 0.25 g
Sodium sulfite 10 g
Sodium metaborate 20 g
Water to make 1 litre.

Obviously not a tricky make but Google doesn't throw up anything much before I have a play has anyone been there, done that?
I don't have easy access to a densitometer so my results are going to be empirical and it would be of interest if results are out there.

Bests
ChrisL

Just noticed stick fingers made it into AN in the title, Mod to change, not editable for me, apologies? C