[Freesurfer] mirroring fsaverage labels between hemispheres

Hi, I have pored over (I think) all of the mailing list postings about cross-hemisphere mapping and I can't quite figure out how to do this.

I have a bunch of labels on fsaverage, and I want to be able to check/visualize the relationship between lh and rh versions of the labels.

I can do mri_label2label to map from fsaverage to fsaverage_sym, but that doesn't do the right thing, and fsaverage doesn't have the same kind of xhemi registration structure that "normal" subjects get with surfreg --xhemi. I guess I could back-project onto a normal subject and then project to fsaverage_sym, but that seems like an unnecessary step.

How can I get mirror-projected labels from fsaverage on fsaverage_sym?

Thanks! Abby