Pointing to git refs should be sufficient for code that's not super volatile. I personally envision using it for onboarding new developers to a code base, in w

Pointing to git refs should be sufficient for code that's not super volatile. I personally envision using it for onboarding new developers to a code base, in which case I think being on an older ref should be fine, since I'm just trying to show the general structure of a project. I could also see using it in a code review context, in which case pointing it at the branch would also be fine. Also, if you look at the schema it generates for a tour, it would be pretty easy to go through and update the line numbers directly in the JSON.