@sjudson before I create a new idea, I just wanted to check if this was intentionally left out or something not included in the original scope.
After setting defaults for task creation, those settings do not apply to the defaults used when checking the box at the bottom of a new email send to set a follow up task. Whether tying in to the existing setting or creating a new setting, it would be nice if creating a task via any method would be customizable to the user.