In the other thread you recommended using the commands
exiftool -a -U -G1 FILE1 > t1.txt
exiftool -a -U -G1 FILE2 > t2.txt
diff t1.txt t2.txt
to check differences in metadata between two files.
Now since you are the developer of the tool, I would suggest to incorporate a feature into it that does that directly in exiftool and would additionally allow the user to specify certain tags to only compare.
For exmaple I could pick certain yet unknown makernotes tags and aget an output file with the differences just in these. That might make digging thorugh metadata a lot easier.
Nice suggestion, but writing a diff engine is somewhat beyond the scope of the ExifTool project.
I have written various scripts that I use myself to do things like this, but they certainly are not ready for distribution. They are fairly messy and not very configurable.
- Phil