I don't think there could be any improvement I could make after V2 before the release of SDXL. (And there is too much unknown about SDXL)
I guess I reach the limitation of SD1.5 at v2. If you like this, please follow me, rate it, and give me a "like".
Many people have trained in this style, but I want to challenge myself to do better.
I think the rainbow color reflection on the hair is an important part of the style; therefore, add "rainbow" in the prompt should show it better.