Yes, that's what I did - made up the volume with concentrate. As I recall, this was a formula used in the newspaper business where lots of film needed to be processed rather quickly. IIRC, Paul Farber wrote an article in the early 80s about the developer and convinced PF to make up kits.

I suspect the large amount of sodium sulfite prevents staining. I don't remember if it tans (hardens) the emulsion or not. I'd give it a try again if I weren't happy with what I'm doing now. Maybe I will anyway.