It's program dependent. Theoretically you need it before ROL deadline. Realistically, you need it before we-have-finished-our-ranking-and-submitted-our-ROL deadline for each program, which is usually before then. How much before then? Impossible to know.
What I have done is reach out to all applicants missing a step score before I finalize my list. I ask when you expect a score. if you don't answer my email, you get unranked. If you tell me some date in the future I write it down. Usually it's a handful of people. I find the last date, and put a reminder on my schedule to check all the missing results -- if there's a new score I assess it (might move you on the rank list, usually down), if there isn't you get removed.