One scenario I would not rule out is a large icy comet moving at large speed straight for a sun. Is there no combination of size and speed for which that would result in a small ice cube in the centre of a sun?
Going back to the sequence of events argument, I think that implies that all universes agree on similar rules like ours (Physics), as we could only deduce this kind of argument with this assumption.
Maybe there is a universe where ice is scorching hot and all sun cores consist of it, and as matter cools it evaporates? Maybe there is even a universe where gravity and orbital mechanics work in a way to produce cube shaped stellar bodies?