He’s an example of a character who doesn’t need to time-travel himself to be pushed by those he loves from another time into potentially changing America ahead of the Revolution.
Case in point: that shot in the Outlander Season 5 trailer of Jamie dressed as a redcoat soldier.
Doing what he has to do to protect Bree might be bad in the grand scheme of things.
Considering he’s currently trying to convincingly fulfill his oath to the Brits by hunting Murtagh while also saving every Scot he can manage, any leverage the British have over him could push him to do a lot that he never would have considered before.