The benefit of recording a VCV bank over a CVVC bank is having an entire naturally recorded transition from note to note, instead of constructing it out of individual VC and CV units. You also get more subtle variations in the pronunciation due to every possible CV showing up 7 times, which results in a more natural sound.
Converting a CVVC bank to VCV will grant none of these benefits, and will sound exactly the same as well-configured CVVC when using the voicebank. If you want to genuinely improve the quality of the voicebank, you will need to rerecord. If you're simply having difficulty with using CVVC voicebanks compared to VCV, you may want to look into Presamp, which will automatically convert USTs without needing to manually edit the notes.
https://ch.nicovideo.jp/delta_kimigatame/blomaga/ar477661