When a point feature is created with two points over the same exact location point, topology will not apply to the added feature and disregards it. I believe this issue should not occur as it should act as if there is a single point.
I was having trouble applying a point I wanted to add to an existing topology feature. I created the feature by copying a feature and turning on the multi-point setting, which turned the line into points, as designed, however, I failed to realize that the single point I wished to keep was actually two points, one on top of the other. I created the feature as a half stage rotation reconstruction method, thinking it was only one point, though when I went to add the point to a topology, it failed to apply it, even though when in the adding stage, it recognized the point, it just seemed to fail to apply it. I just troubleshot the issue. The above statement is what I have deduced.