Part of me thinks, isn't multiple singing styles kinda already there in existing reclists? I mean, I don't know if they're all possible in the existing reclists right now, but it gets me thinking: With VCV, you have the CV parts shown as "- あ" and the like, so one could just make another alias or two for those samples and you've got compatibility with CV .usts. Same thing only easier with CV VC: Usually in CV VC stuff the CV samples are notated like a normal CV voicebank, so they could just be easily used as CV banks as well.
The combination, however...I guess it depends on how you approach it. How did you approach it?
The samples here sound pretty nice. But the question is: Is it practical? Is there any need to cover all styles? I think these questions are left up to the users themselves.