First, thanks for a very useful app!
I use this to adjust CreatorTool metadata in PDFs so that my Fujitsu ScanSnap software will do OCR on any PDF rather than just the ones I actually scanned myself.
I do the same operation every time I use the app, but currently I have to manually erase the metadata and cut and paste from the defaults dialog.
It would be handy if a button could "set metadata to defaults"