Originally Posted by mornington
That's a great workaround, thanks.
I'm glad it helps. I spent some time adding it, and you're the first to even mention using it. Be aware that it works exactly like autosort/automerge, not like the Merge function. (That's what you asked for, but it may not be what you wanted
Merge is designed to merge metadata and formats. Autosort/automerge only merges formats, not metadata. The first record that is processed will have all the metadata, and the metadata from the second and subsequent "matching" books will be lost.
Before you delete your source library, you may want to search in destination to see if any records are missing metadata you think should be there.
This relates to the "duplicates" finding issue that has several threads here. I keep threatening to write something like that, but not having the time. I suspect finding the dupes and manually merging by selecting the "best" record might be what you want. Searching for those threads will give you some code or methods for finding dupes.