Actions lists are simple To Do lists, only they are written as actions. One verb and one noun for every action. A very efficient combination, rediscovering the way some human languages work, if not every one.
Actions lists are more than simple To Do lists, when the actions are linked together by causality or reason, and ordered to furbish a plan. The first action on the list is the next action, the others are what comes up next, i.e. after what to do now. Ultimately, next actions are useful only when they are next actions for now.
Action lists for Now is what's needed, not a big bag of Next actions. Something like a list of Prioritary Projects, with the related actions for Now that needs to be reminded. Each project's list only contain next actions, and so are well be kept aside, reviewed when what comes now is done, in some ultimate tense.