There is indeed functionality missing to paste into a new empty voice.
As a workaround for now:
- place the caret where you’d like to paste
- Shift+V for new voice
- enter one note
- delete that note (backpsace)
- paste
I’ll look at making ‘paste to new voice’ available in a future patch release.
The other piece of functionality that may or may not help your use case would be, to paste into an existing mode with chord mode enabled (effectively not deleting existing notes in the voice you are pasting too). That’s not possible yet, but it is on our roadmap.