It could be annoying for someone in a regular ward who occasionally looked up other members in the stake if it remembered the last ward that was being viewed, so I'm not sure if keeping track of the most recent ward would be the best solution – however, I can see how it would be more convenient for someone in an out-of-unit calling to have it default to the out-of-unit ward. It might be worth sending in-app feedback under Help > Contact Us in Member Tools. They might be able to put in some code to default to the out-of-unit ward by default for out-of-unit leaders; or, they might be able to add a setting where you can choose what you want your default ward to be.
Samuel Bradshaw • If you desire to serve God, you are called to the work.