@Leo, I use your suggestion to open a linked lister by default for images. Works great.
However, it does not work when I open an image file via a button that lists all files on the desktop: Go /desktop NEWTAB=findexisting FOLDERCONTENT=showempty,norecurse. Instead, the linked viewer displays a (the first?) file of the currenly opened folder (which is not /desktop).
This might be expected behavior, but is there a workaround to still use the internal viewer by default (without disabling the linked-mode)?