I have been using Dignan NFC-41 developer for quite a long time, but there are some negative points that I couldn't resolve until yet: the first bath doesn't last that long, after the tenth development in a weekly basis, you already see thin negatives; the color shift to green in negative (magenta in positive) is possible to fix but somehow annoying. Another opinion that may be right is that modern films have thin layers and cannot hold enough CD4 to the second bath. I have tried to extend the times for both A e B baths or to put a few ml of bath A in bath B.
The great expected advantages of Dignan method for amateurs are: no need of temperature and cost reduction by using only small amount of CD4 each time. The first advantage, if you want to get better colors, will disappear because maybe you need to use temperature. The second advantage did not prove because the first bath goes bad within some time. Unless you develop every day, you will not save much money with the developer.
I already though about just using a mixed developer (A+B) in a one shot developer using temperature. But the problem of the shelf life of bath A would still exist.
Further searchs at internet, lead me to this very clever suggestion of Bill Williams at APUG.
I already have results of using it. Unfortunately, I made a small mistake, using more carbonate than proposed. Nevertheless, the pictures showed great potential. Maybe next time will be even better.