I have a way myself, but you know, life is all about trying new stuff. Is literally scheduling a Asynchronous task to copy a folder better then just a single line of code to setAutoSave to false, then unlod+load level? Are there any differences?
I personally use that one: https://forums.pocketmine.net/threads/how-to-reset-map.15404/#post-149954 (Last post). I use it because it doesnt require a task and also seems to be very simple.
I think it doesnt work, as I tested that by myself the levels were only reset when I restarted the server, I also did loadLevel()