I have several ongoing image projects (photo books, etc) which I am unable to complete during a single "operating" session. It would be great to save the array of open tabs and browser configuration/location etc., into a
named project file, then restore those settings another time by the simple action of opening the named settings (that is: "project") file.
Additionally:
It would be great to have several projects open at once, in which case the projects would be an additional level of abstraction represented in the GUI as another row of tabs "above" the document tabs. "Tabs within tabs", if you will.
A project tab could have within it a browser tab (or two

), multiple image tabs, compare tabs, etc. Each project would be opened into a project tab and, when opening, all of the project's subordinate tabs would reopen automatically, reloading all settings and options for that project. Consider how much time this would save those of us who work with many images (and for many different purposes) at once.
Such an extra level of organization (which reflects how many of us actually work) is missing from
every file manager/image viewer I am aware of.