Or, the lesser known option is to create a subclip.

Tools / Render to New Track with a lossless intermediate.

or

Do your syncing in a separate Vegas project and use that project as a nested project in your master project.

Thanks for the reply!

Render to New Track is a good option, but I could imagine this taking a long time and doubling my project file size since every shot will have to be exported again lossless.

The nested timeline suggestion works rather well, except I now can't revert back to the original files in order to export separate tracks of audio as an aaf.

Ideally I was hoping there was a way audio and video could be merged into one file within the media bin, like in Premiere. Nested timelines is definitely the closest as I can still add takes within the clip from the trimmer, it's just the lack of being able to remove the nested timeline that I'm a little concerned about.

Or, the lesser known option is to create a subclip.

Creating a subclip sadly doesn't merge sound and video together, it only creates subclips of both individually.

@Owen-Barbet try grouping them first.