You can "Pick Nth instance" in the System conditions.
Then use object.Count-4 as the Nth instance to check the frame.
Do the same for object.Count-3 and object.Count-2
If all have same frame as the new object, then change it to something different.
Something like that. This is one way to do it. You can also use a variable to count how many repeats there are, and reset it if it doesn't repeat. If variable is above a number, then choose accordingly.