Following a repetitive path is probably beneficial for weight loss because you can track your workout a little better. I don't cycle for weight loss though so but more for just the physical activity and funsies. If I was doing it for weight loss though I would imagine I'd try to find a path that is easy to follow and a good distance for my physical state. What you're doing is great so continue with that and you'll be fine. If you haven't already, I'd suggest browsing the Clydesdales/Athena's topic for more advice on cycling as a weight loss solution.