Changing sequence in a live campaign
the fact that the sequence cannot be changes once the campaign is running is really downside, you learn as you go, you don't always know at the beginning what will be the response, the feedback, the acceptance and to what. the ability to alter is crucial. at least allow to freeze (from a certain contact onwards), make the changes and carry on. also the fact that for every such small think you ask to upgrade is not legit.