Using Ctrl+Right-click or Shift+Right-click to call the Windows context menu instead of XnView own one.
Possible, but not discoverable. How can we let the user know about this?
I don't know about coding so I don't know how hard this feature could be to implement. I only know ACDSee has it which is pretty handy.
Of course, there's no hint in any place to tell the user that Ctrl+Right click (as example) launches system context menu instead of XnView one... But that's not enough reason to not implement it.
And you could always do a small trick: Put a toggle in Settings which says something like "Ctrl+Right click launches either system context menu or "XnView one"... In this way, by just reading the available options, you'd learn about it. Not because I do actually want to change Right-click to Windows context menu, and therefore Ctrl+Right-click to XnView one, but because I want to teach
the user about this feature...
(also not very cross-platform IMHO)
I don't know if either Linux or Mac offer context menus, and, of course, in Macs you don't have either Right-click or Ctrl... But if there were context menus in theses OSes, my suggestion should be read as "launch OS context menu instead of XnView one through a modified way of the process you normally use to call that context menu".
Moreover, when I say Ctrl+Right-Click in Windows you should also read Ctrl+"That key on the right bottom of the keyboard I haven't ever seen anybody actually using".