IS does report on unique opens and total opens, however, the open itself is subjective as each email client reports opens on different conditions so it’s a limited usefulness in value. There are other methods like using tracking pixels but again, the results are affected by what email client the email is reportedly being opened in. However, even the gross opens I don’t think IS tracks who that is when open is reported multiple times, but rather, just the count itself. Now clicks are a more certain value but raising a tag only tells you it was clicked, not if someone clicked it multiple times. For that, you could use the tag to trigger a field counter using a tool by Plus This or other offerings so that one is more possible to do.