We have added a new way to create an engaged audience. You can now use the new attribute 'Email Engagement Score' to create this segment, by adding 'greater than 2.' See below.
This will create an audience of people who are actively engaging with the campaigns, and as long as you keep it dynamic, you won't have to update it once it is set.
You can also do the same thing to remove people with scores of 2 or below, as you likely don't want to send them an email if their engagement score is that low. We will start automatically removing people with a 0 score