This is just to signal that I am currently using Moersch Sepia with the Lodima Paper with very good results. I used to develop Azo using catechol/sepia two baths but I have now switched to Sepia for ease of use and nice contrast. I have used once Meritol with Lodima, which produced a warmer tone but needed a much longer developping time (1+14 dilution in both cases).
I am not taking much care about the exhaustion of the concentrate in the opened bottle but never noticed anything detrimental with the Sepia developer.
Moersch also now has an amidol liquid formula which I may try...but the result have to be dramatically better for me to use a more expensive and "dirty" developer to work with!