To be honest, I actually prefer not having any established fanon headcanon. I find popular headcanon is usually OOC or ruins the fandom/pairing/character for me since in my experience popular fanon tends to be completely opposite canon characterization. This is what ruined TFA fic for me (and what happens in a lot of large fandoms).

YMMV but I think the screen time we got in RO gave enough characterization to write fic. The movie did a pretty good job of getting personalities across in such a small amount of time.