My approach is very similar:

1. I put together backing tracks in BiaB,
2. Export a single track to SynthV
3. Develop the melody and lyrics in SynthV
4. Export the vocals to my DAW
5. Export the BiaB tracks to my DAW

SynthV doesn't always play nice with DAWs, and I can export the vocal and aspiration tracks as separate tracks.

Once the vocals are done, I'll generally keep SynthV running when I'm working the DAW. That way, if I want to make a quick change to the vocal, I don't have to wait for the entire vocal to regenerate. I just Alt+Tab over to SynthV, make the changes, export, and Alt+Tab back to the DAW. The DAW sees the vocal track is modified, and automatically loads the new files.

When I'm in the DAW, I'll open up BiaB when I want to generate additional backing tracks, and export them into my DAW. But the load times are generally small, and I only need BiaB when I'm exploring additional or alternate instruments.

Breaking it down like this also it keeps me focused on one task at a time with the best tool for the task:

1. BiaB for backing tracks;
2. SynthV for developing vocalsl
3. DAW for mixing and arranging

-- David Cuny
My virtual singer development blog

Vocal control, you say. Never heard of it. Is that some kind of ProTools thing?