Hey Chris -
Great question. What you're seeing now is that the app remembers last position for a vertical but only in the temporary memory. If you swipe more than two pages ahead and then go back, it resets. So there's no real way to designate that ahead of time.
In the next release (due out Feb 12), we are introducing the ability to disable left and right swipe (and scrubber) in an issue—the idea being that you can control the users' navigation around an "issue" using only jump links. That's one possible solution here - then it would be easy to have a link that took somebody not only to Vertical X, but also to Object Y in that vertical, where Object Y could be on the second slide and then they could swipe up and down on that vertical. Would that work?