Can't sync audio by timecode, pasted into multicam timeline

Hi. If you create a multicam clip, the single poly audio track is not easily editable by individual source track.

So following Jim Simon's recommendation, I mute the multicam audio and paste my individual audio tracks into the multicam timeline. This allows easy track-based editing of audio.

But... it does not seem possible to sync (by timecode) the pasted audio tracks to the multicam Video track.

3 cameras and an F6 recorder were Tentacle jam synced and so all have timecode. Is this a limitation of a multicam timeline?