I hate to say it but can you copy strand and have the ability to load only part of a show from disk. ie: just the patch.
god, how can str**d be right???
I have removed your request from the list, because you can already do this.
You can load the entire show, and then use selective wipe-all to wipe everything that isn't needed.
Merging it into an existing show might be trickier though.