GigaPixel Standalone vs Open with...(Mac)

When I open an image directly (drag and drop or File>Open…) I have the option of selecting a new filename (i.e. Save As…) and preferences for appending suffixes are available.

However, if I use Open With… from another app (in my case Mylio or the Finder in Mac) the preferences above are no longer available and I have no option for changing the filename before saving - the only option GigaPixel offers is “Apply”. This option overwrites the original file.

This is a huge problem because I cannot use any Topaz product from within Mylio (or using “Open With…” in the Finder) without losing my original file. (I could manually duplicate the photos I want to edit first but that would be time consuming and annoying!).

Am I missing something? Is this behaviour a bug or a feature (and if a feature - why)? Any help would be appreciated…