Thanks again for another great tool!

I'm mostly using this to combine FSH together as to not waste space (For example, an HD zoom 4 that uses 4 256x256 FSH when it only needs 1). However, I am seeing my file sizes increase rather than decrease.
My particular BAT is a long and narrow, so I can merge the 16 zoom 4 FSH into 3. The end file size is not as small as I think it should be (Especially compared to the original model with just the other 13 FSH removed).
I "save selected files" in reader, open in GIMP, edit, save (with FShWrite compression on), and "insert and compress".
Something missing?