I'm probably several years away from having GCS. I have heard that scar tissue from having an orchi can be an issue with GCS. Is this true? I'm interested in having an orchi done in the meantime, but don't want to damage anything for the future.

Get an Inguinal orchiectomy. It doesn't do anything to the scrotum.

It can be an issue if the surgeon is not familiar with the gcs procedure. if they are then it should not be an issue. I had a bilateral and have had a consult for GCS they did not have any issues with the scar as of yet. I would suggest you have someone do it that is familiar with the procedure