You could put a transport (either using a transporter or any entity) back to the beginning of the level prior to entering the win zone, and you could go back to the start point of that level, however it will not reset any events, entities, characters, weapons, etc.
Once you enter the win zone, the engine progresses to the next level in the build list, and we currently have no control over that. It would be a good thing to ask Santa for the next time we see an update coming.
Best.
I'm sorry, my answers are limited. You must ask the right question.
