Ohh, we haven’t gotten too far in our multiplayer play through (since we are thinking about waiting for full release). But if that is the case it could be a nice work around, I do know trying to talk to your friends companion will result in a “I’m busy now”, but from what I saw the camp cutscenes always have the host (or party leader as your said) as the PC. Again I may be wrong, thanks for the reply.
Weird. Regardless if we talk about the game version from release or from not so long ago ( like 2-4 months) the cinematic would always be centered around the character who started a given dialogue.
But yes, you can't start dialogues with your friends companions, it worked this way in Divinity: original sin 2 and it will most likely remain in such a way.
Small edit:
I definitely recommend waiting for the full release. It's just around the corner.
As a way to wait you can listen to the soundtrack when going to work etc this way you can pretend you actually play the game. While softly crying on the inside waiting for the release.