Can I use Duty officers that I buy for dilithium or EDCs for missions where there is an exchange of duty officers? I have been using Doffs that I can get back with ease for missions where I exchange them for another Doff but the two times I tried no Doff was returned. Not sure if I needed a Critical success or what. The mission descriptions should include what kind of success needed for attaining the Doff. Is there anywhere to go to get a list of Doff missions and their rewards and requirements? I also think that the repeatable chains should have a listing how many times you done them and what rewards you have already gotten from them.