You know what fluff it. Imma post my understanding of the SR formula.

As with most ops it depends on the country doing the op as much as the country receiving it. Now. In my experience the max a country can lose is ~4% of its population. However, if the max is above 7% of the total pop of the country doing the op, it caps at that point. Despite knowing that, I still will use CDs to save stock lol