Many strollers come with 5 point harnesses where the top straps can be undone creating a 3 point. You can use whichever mode you feel like that day. For a stroller IMO, the harness type doesn't matter much when you are on normal terrain. I guess if there is a chance of the stroller tipping I would go 5 pt. Peg has a floating harness so you can use the 5 pt but still get the freedom of movement.