Open with -> Associated editor (F4) opens a single file only

[szfjozsef]

Often working with multiple files comes the need to open/edit these in an image editor.
Here is my case - I configured as external editor Photoshop. Then, working with images for a catalog, editing (downsizing, adjusting, etc.) is needed with the external editor (here forget the built-in editing capabilities of xnview, these images are on multiple layers, etc.)

So here is the bug feature request: invoking the external editor (F4) opens one single file, instead of opening all selected files. The basic expectation is: select random files and then edit all those by hitting F4.

It is possible to open the seleced files in the preconfigured external editor, regardless of whichever was selected first?

[xnview]

The ShellExecute function used command is only for one file. The only way is to open multiple files by opening multiple instance of app...

[szfjozsef]

Technically invoking ShellExecute for every file will do the trick, right? Only that it is a little bit slow. Other software warns over 10 selected files as "Are you sure you want to open 25 files?"