To be honest, I really dislike the current way how quests are automatically activated as soon as one milestone of the current active quest is completed.
This is specifically annoying when doing zone quests that contain several milestones that one has to complete one after the other.
I complete a milestone and then automatically a quest that is not part of the current zone quest is activated, and most of the time in a completely different zone. So when I want to pursue one specific zone quest (story quest for that zone) and I have completed one milestone, I have to open the journal, search my zone and activate it again. And again. And again.
That is pretty annoying.
Let alone that in case I forgot that it is not automatically pointing to the follow on milestone I completely run into a completely wrong direction until I realize that I am pursuing the wrong quest marker.