The little root sprouting up (in blue), I would keep that in the small pot but move the larger one to a large pot. And To make the root grow larger without the stems getting huge as quickly I could prune the largest stem (in red). I know on a tree this makes the trunk sort of grow differently, with a new lead branch. I wonder what pruning like that would do to this plant.
Will new main roots pop up as it grows or is that a product of successful germination?