This thread happened to catch me while I was re-exploring the Sith Warrior class so I figured I'd stick with Vette. I have experimented, when finding a dialogue trigger, with switching companions out and running back over the same point to see what happens but so far have had no joy with it. Perhaps the triggers have a cooldown. Has anyone found differently?
I *think* they'll trigger once a day. I know I ran into a line with Kailyo at the Starcluster Casino twice during the Chevin event and then was trying to retrigger it later. I tried logging out and then back in, but it didn't trigger again that day. Should head back and try it again just to see.
One of the things I'm not sure about is whether you run over the trigger spot on your speeder, if you go back with your companion it'll trigger. There's another spot on Nar Shaddaa that I know triggers Kailyo, but when I tried it the other day I didn't have any luck and it may have been because I used a speeder the first time through. So the triggers may be tied to where your character has been more so than your companion.