H&W Control is another one I've always wanted to try with general purpose film (not microfilm) to see if decent speed can be maintained with extreme low contrast.

Alan, is this the actual formula or an approximation from a patent?

It would clearly operate at a much higher pH than D-512, and with its lower sulfite content and very small concentration of secondary agent, it resembles the various experimental formulas propsed in FDC as modifications to POTA where the addition of a small amount of a secondary superadditive agent allows for a lower concentration of Phenidone (and less sulfite).

What I always find funny are formulas in which weight quantities are given with precision to hundredths (or even thousandths!?) of a gram.