@Goorawin Re: Layout. I am using the non-GTK3 versions, with which I am more comfortable.
@Carmelo_DrRaw Using the raw from [PlayRaw] Falkert - Austrian Landscape, I go into the menu and select the closest named lens (exiftool says it is a AF-S Nikkor 18-35mm f/3.5-4.5G ED). However, when I do anything in PhotoFlow including resizing the app window, the setting changes back into Unknown lens.