While working with the segments, I noticed these 2 aspects:
A. It is not very intuitive that if I leave the space blank it will fetch users who opened 1, 2 or 100 times.
B . Usually we have the option "greater than or equal to" in one dropdown option:
In Opens I need to select 2 different things to take users who opened 2 or more for eg.
Maybe this can be fixed one day so that we create lighter segments.
I experience similar issues.