Copy tax book from tax book?

Hi All-

I think I'm asking the impossible but we're preparing to create a new tax book and the usual process will likely require a sizable bit of manipulation.

Typically, we'd:

1. Create the new tax book

2. Run Initial mass copy

3. Prepare a file for changes to the assets

4. Upload the modifications using the Tax Book Upload Interface

The business is concerned that they're going to have to perform a ton of manual scrubbing to commit the changes to the tax book. They believe it would be easier to copy the new book from an old book.

I couldn't find any way to do this in my research, so I'm guessing it's a no go, but has anybody faced this requirement before?