-- This brings up another thought -- would it be practical to add a "fuzzy" option to your binary compare, something like you open the epub and check the hash of the largest folder for a match?
(and should I bring this question up in the Duplicate Check thread?)
You are correct that it is a question for the Find Duplicates thread, but I will give you an answer here anyways. I have no interest at this point in changing the plugin to start looking at ePub content - it will dramatically slow it down by many orders of magnitude and opens the door for a number of other issues which I am quite happy to avoid.
Yeah, the more I thought about it I realized just grabbing the pertinent CRC out of the zip file header wouldn't be that simple.
So I added 7zipFM to the OpenWith plugin. So if I suspect two epubs are identical (except for metadata/timestamps) I can quickly eyeball the CRC's of the OEPBS/OPS/whatever folder.
Works for me
By the way -- Find Duplicates is a truly elegant example of good design & functionality.
Now if I could only apply it to the boxes of books in my closet, and attic, and basement ...