I have this weird hc where Green Sun has its time working in a weird way. Like, when you enter it (somehow) you can m8ve towards or out its center. Hovewer changing the direction results in you moving between states of green sun. That way you can travel to any point of its existence. However if you are uncareful (there is close to no way of telling at which point are you going to end), you might arive to the point of its death. And there is no 'before' to which you can return s7nce time is dead.

I mean, if we go by Canon, the Green Sun actually being a physical thing in the Furthest Ring, if anything, kind of acts like an Euclidean Anchor- It gives the Furthest Ring a sense of Time and Space, much like the cracks do.