I feel overwhelmed with this cuteness. :-/
Dragon Age Origins (And I think 2 and Inquisition too) Circumvented this problem by allowing you to manage a companion while in the "Camp." That said, I feel like of the companions, Astarion is the most content to sit around, while Laezel is the least content.
Problem its, that in both Dragon Age you are essential for the story ...
No one else can demand to fulfill those old contracts, no one else can kill the archdemon ... only Gray Warden can.
No one else can close the breaches ... only your PC can (cant remember any specific title, they used ... only inquisitor).
Here you have bunch of independend existences that are together, just bcs if one of them find any way to get rid of that tadpole, the rest dont need to look futher. :-/ To say it kinda harsh ... your character actualy dont matter, and if there will be none, for others there is no huge change.
Therefore "you" cannot manage companions in camp, its true they dont have much reasons to stay ... yet they have even less reasons to do some work you give them meanwhile.
The only way i can imagine to manage "curently unused" (notice that i on purpose didnt use words "in camp") is scatter them to the world, and keep them as "temporary" companions ...
Wyll > Tracking goblins.
Lae'zel > Tracking her kin.
Astarion > Hunting in wilds to feed ... but to provide dinner for party, officialy. :P
Shadowheart > Finding the healer: She could show up in front of Auntie house.
Gale > Finging rare artifacts: Spawn him in some distant promixity of some artifacts saying something like "i can feel it, it should be around here somewhere".
etc. Just let them continue their story.
It would then not be like "stay in camp, bcs i, the compeltely random dude with no autority over you, just said so" ...
It would be more like "ok, lets get agreement, everyone shall look around ... and we meet here every evening, sharing what we found."