This request applies to: Color Efex Pro, Analog Efex Pro, HDR Efex Pro and Silver Efex Pro;
The File menu provides the option to Quit (Ctrl + Q) - whilst a button is provided to Cancel … the end result is the same … these should be named consistently.
When multiple images are opened within any of these Nik tools there is no ability to close only selected image(s) … currently, both Quit and Cancel will close the entire application.
PS. I have reached my limit of allowable votes.