I haven't seen the movie in a while now but I remember Cobb or maybe Mag placing the top inside of a safe, spinning it, and locking it up while they were in lim

I haven't seen the movie in a while now but I remember Cobb or maybe Mag placing the top inside of a safe, spinning it, and locking it up while they were in limbo. The top would appear to spin forever at in dreams closer to reality or reality itself because of how much slower time flows at the lower levels. However, the top will not spin infinitely. It will eventually stop when it finishes spinning in the deep nested dream reality, therefore I don't think it is necessarily a great indicator of reality if it topples over or not because it will stop spinning eventually. At least this is how I read it. To be honest I didn't really think the top made a lot of sense but I think this is what it was intended to mean.