Thank you. I'm gonna explore a code-based solution first (I think I can extend either Engineer or Mechjeb to display the info I want), but if I can't get that, I'll just use a dummy vessel
Edit: I got Kerbal Engineer to display it with a little bit of coding. They have a lot of internal code for viewing the fine details of something's orbit, though it looks like it's mostly nonsense in stock. So far RSS/Principia's results seem plausible though.
