How to combine surfaces?

[binarybottle]

I need to propagate surface labels through cortical volumes, but because mindboggle now combines ants and freesurfer segmentations and will soon accept modifications to surface labels, I don't have separate left/right cortical volume masks to fill with ants label propagation and can't use fs's label propagation. Should I create a separate workflow for each hemisphere, and combine the altered, labeled surfaces in a separate workflow prior to propagation?

[binarybottle]

Or pull out the volume workflow and run it after the surface workflow and call the surface workflow's DataSink outputs? Or perhaps I should use FS filled and aseg volume labels to split the cortical masks and simply propagate each hemisphere's labels within these hemi-masks...

[binarybottle]

I removed medial labels from FreeSurfer's aseg label volume, propagated the remaining left/right labels through the Atropos brain, and split the brain into left and right masks. This SplitBrain iterable ensures that all label volumes are also split into left and right sides.