You may be horrified to learn that at Monash until recently (not sure if still true or not) one of the measures was, I shit you not, “Cumulative Impact Factor”, which is the *sum* of the IFs of the journal of each of your papers.
Yes, I am horrified.
I wonder, do/did they go to the trouble to use the historical IF at the time each paper was published, or admit it's all meaningless and use the most recently made-up value?