That brings back memories of the late 60s when M&B Dagenham manufactured Mydoneg (and Mydoprint for RA4) and my colleagues always complaining that Eastman Kodak virtually gave away its chemistry to ensure paper sales. The whole shop was then moved off site to Brentwood under the Champion name and a single Armstrad computer ran the whole business.
On the other hand Tetenal says in the Colortec kit instructions that it is 3:15 excluding fill and drain.
The only pro lab I know has different developing times depending on the film, the difference is small but needed to have the same output in all of them.
Hi, the original Trebla is long since defunct. CPAC was originally formed as the "Computerized Pollution Abatement Corporation" back before "pollution abatement" was seen as a significant thing, with a big emphasis on silver recovery equipment for photofinishing. But by the 1980s effluent control had become one of the biggest issues for photofinishers. Somewhere along the line both Trebla, a photochemical manufacturer in the Midwest US, and CPAC saw the benefit of combining, and a long-standing union was formed. So photofinishers could buy their chemicals and effluent-control equipment from the same outfit, with sales engineers who would make sure that problems were solved.. They were big players in the beginning of the mini-lab days. But when the conventional film and processing business began to collapse, around late-2000s (?), I think they substantially closed down, although I don't have specific info on this.