She is most prominent in the Burke scene and she is one of the most prominent characters during the party even if you're not on her path. So she was the most prominent character in both parts of the last episode in my opinion. Compare her to Isabella or Jill for example who had pretty small roles if you're MC wasn't on their path.
J&M, while prominent in the Burke part, also only had minor roles during the party.
I haven't counted it, but I wouldn't be surprised if Sage was featured on more renders of the last episode than any other LI.