I guess we require the first developer to give a high contrast while producing a fine grain. Using paper developer, I was able to get the contrast but the grain was always a problem. I wonder what is the problem with developing films in paper developers. All the guidelines (Ilford etc..) recommend not to prolong the time of development. What are the side effects?
When I use the Fomadon LQR I have no problem with grain. I think I can let the film in the developer quite long without any side effects. I have never tried to brew D67 when LQR is quite cheap.
The amount of thiocyanate or hypo have to be calibrated for each kind of film separately. Thus Adox CHS 25 and CHS 100 need different amount. If I am not wrong, generally, the lower the speed of the film the more silver and thus the more halide-solvent needed.
Second, if we decide to keep the film in the developer longer, the halide-solvent is going to work more and thus smaller amount is needed. In this respect, it may be easier to settle on one time in the developer (previously tested as negative process) and then calibrate the amount of solvent agent.
I think when Kodak recommended some developer with some amount of solvent agent, they meant it as suitable solution for their film like reversal tri-x or so.
But maybe I am totally wrong.
Vaclav