When I go to work, I don't just put my head down and do 8 hours of work without talking to anyone. I'm frequently talking to the people around me about what I'm doing or what they're doing or what we're doing together. Everyone that I've ever worked with does this.
Do you often work to remove a magical parasite of extraterrestrial origin from your brain?
If not, then I would venture to assume that you are put a little less pressure on you than on our heroes.

Your suggestion that people should just have all of their conversations at night
And that is funny ...
Since i never sugested that.

What im actualy sugesting, is keep things as they are now:
In field, we are focused on curent matters.
In camp, where we have time, we can talk about other things.
From a spell slot perspective, I am perfectly willing to assume that he's using Minor Illusion or is using magic in a way that isn't perfectly encapsulated in an existing cantrip. He's playing with a simple illusion, not disintegrating someone.
Cantrip that he unlearn once the conversation is done?
Yeah, why not ...
I'm fine with that, too, if they can make the transitions between them convincing. I still think they should happen at various times throughout the day.
I dunno ...
I was thinking about allowing to talk with companions any time you visit the camp ... it still feels off to return to camp to "just talk" ... but to be honest, whole returning to camp at any time except for sleeping is quite odd and seem completely iracional ...
So, i presume it would be acceptable. :-/