With the way things are currently set up, these steps couldn't be achieved within the Smart List stage; only in Flow.
Ex: a trigger campaign requires a waiting period before SF will have updated the other fields used as filters, so this is additional segmentation is done using a Member of Smart List choice in Flow.
Ex: a trigger campaign uses a SF field in Flow that determines send time optimization (this is achieved through a series of wait steps and constraints using different values of the SF field.
Can segments be used for testing (i.e. dynamic content)? I could use segments to randomize our entire database and test different subjects and copy that way, but will I be able to track the results?
Also, how would I then test extensive design changes (HTML) beyond just using different images within dynamic content?