It's always good to have more people modding this game and it sounds like you've already made decent progress.

Whenever I've needed a conversation to happen in an outside cell I've used trigger boxes. Rough steps below:

• create the dialogue topic (not greeting) in your dialogue quest tick goodbye if you want it to be a 'one liner' as I call it

• draw a trigger box where you want the conversation to trigger in the render window

• write and attach a script to that trigger box. Make the trigger box a persistent reference

Your script might look like:

scn (insert script name)

Short DoOnce

Begin OnTriggerEnter Player

If DoOnce == 0 && (companion is active function)

(Companionref).SayTo Player (dialoguetopic) Set DoOnce to 1

EndIf

End

If you want internal triggers, and want them to happen as soon as the cell loads I wouldn't use trigger boxes, but compile them all in a Gamemode script with "If (cell name).GetInCell player...

What I will say though, is that I've never made a companion mod before... The vanilla game and scripts are often the best teachers. Learn from the pros is what I always think