Hi Radhu, I did try it with a large number of different films, and this developer is still one of my favorites. But I was not specifically focused on contrasty technical emulsions (where I actually had more luck with the Jarai metol-phosphate developer I posted in the resource), if this is what you would like to know.
One thing I found is that for maximum contrast dampening effect it pays to do two things. First, pH of A concentrate should be adjusted to ~7.8 (with whatever you may have on hand). This is because sodium sulfite can be as high as 10.5 (10% solution) here in Canada, and this results in an overly active developer with large grain showing up in highlights. Second, do a series of preliminary tests on a specific film. First, you should determine the time in the A bath (1+19) when the highlights of images appear. They will be brownish in appearance. This time can be as short as 5 min for Foma 100 and as long as 10-12 minutes for some others. Then in the same way you need to determine the time of barely adequate development in B (1+19) only (can be 6 min for Foma 100 and a long as 15 minutes for several ISO 400 films I tried). Then you combine the results to develop in A and then in A+B. In hindsight, it makes sense, since solution A is actually very close to a metol-sulfite developer once known as "Mimosa", except it is used very dilute; the B bath is a very active PQ developer that by itself has pH 10.5 (diluted), close to the one suggested by Wiederman, so it will result in a relatively large grain. However, A+B has pH 9.5, so the result is similar to Ilford Ilfosol, but with contrast reduction. I have a suspicion, but cannot be sure for now, that it also works best with thicker emulsions, of which Adox Silvermax is one, and Ilford Pan F is another. The reason is probably that metol retained in the emulsion depth contributes more to the image once pH raises upon mixing of A and B.
I am eyeing CMS 20 but at present I am occupied with projects that benefit from a temporary heat wave.
