I can confirm that this did, in fact, work as expected.
I had a 3Tb VBK on the full extent and the same job had about 400Gb of VRB files on the destination extent.
I disabled the backup job.
I renamed the folder with the VBK temporarily and robocopied it over to the destination extent.
Once completed I deleted the folder off of the full extent
I then robocopied the folder with the VRB files from the destination extent over to the other extent just so I can keep them separated like they were.
I renamed the folder with the VBK file back to it's original name and performed a Re-Scan on the Scale-Out Repository.
The job stated that changes were detected and updated the job. I then pulled the properties of the disk backups for the job and all of the files showed the new locations.
I ran an incremental backup which ran successfully and copied the incremental data to the correct/new location.