Sub-trigger or trigger within task
As of now, trigger (event, state, app, time etc) can be defined only as start event of any profile. Once any task is running with this trigger, there is no way to pause running task and wait till another event occur. This brings limitation to define complex task/profiles.
We can use workaround of activating another profile with that task, but that's workaround only and not best solution.
I am not software person, but my guess, we have all trigger elements readily available to do this. It's about putting these trigger element within task and defining algorithm to use this.
I believe, this will lead tasker capability to next level.