When I suggested Metol as a substitute for Atomal I did so for a number of reasons. Among these are the fact that both chemicals are related in structure and belong to the same Kendall-Pelz group being based on aminophenol. Developing agents such as CD-1 are based on paraphenylene diamine and are in a different group. Their use proposes some different problems which Calbe may have solved with chemicals which do not appear in the MSDS. Another consideration was ease of access and price. The color developing agents may be hard to find and are usually more expensive. If Metol does not produce fine enough grain then Glycin is another possibility. It too is based on the aminophenol structure but is less active than Metol. It is also in the same KP group as Metol. By being less active it probably behaves more like Atomal. But again more expensive and harder to obtain for some in other parts of the world.
No matter what developing agent is substituted for Atomal, it is highly unlikely that the resulting developer will exhibit all the properties of the original Atomal developer.