Now Cubase 10 support ARA where you could easily interchange audio files to edit between Melodyne and Vocalign
For those not familiar of what ARA IS all about here is a brief:
Audio Random Access (commonly abbreviated to ARA) is an extension for audio plug-in interfaces, such as AU, VST and RTAS. It was developed in a collaboration between Celemony Software and PreSonus
ARA increases the amount of communication possible between digital audio workstation (DAW) software and a plug-in, allowing them to exchange key information, such as audio data, tempo, pitch, and rhythm, for an entire song, rather than just at the moment of playback. This removes the need for audio material to be transferred to & from the plug-in and allows that plug-in to be used as a more closely integrated part of the DAW's overall interface.