Limited Settler Sandbox range

[Xevins]

So I was building Spectacle Island to be just for me and the companions with a specific building built around each character individually.

The natural problem however is Companions use the same AI as settlers at your settlements and as a result just wander aimlessly if they don't have work.

Would it be at all possible to make a mod that allows you to in some way dictate the radius of settler (Or even just companion) sandboxing?

For instance if I built a Power Armor garage for Danse I would like to have him stay in there interacting with objects in that building.

I understand if this isn't possible.