The surrounding swirling lines seem to stand for themselves so I didn't choose to densely quilt them and in fact, I will just free motion outline the dark swirls.
The light blue circular area that surrounds the entire center medallion didn't call for attention so a simple meandered fire-like fill seemed to work fine.
Moving outward from here, it's decision time. How to treat the flared areas at the quilt tops edge. When stitch patterns are not immediately/intuitively obvious, I sleep on it.. and so I will. I think I know what I want, but I'll know better with a fresh brain and eyes. Sometimes you must stop and rest the brain and eyeballs.