Drag and drop with shift+alt

I went to edit file types -> "all files and folders" and changed action: drag and drop with alt key to:

copy QUEUE=none FLATVIEWCOPY=single MOVEWITHSHIFT 

But it always copies file (although when dragging the tooltip shows info that files will be moved!), no matter whether I held shift or not.
What I'm trying to do is:
copy files without recreating folder structure when holding alt
move files without recreating folder structure when holding alt+shift
Also I would like to use the same modifier when just moving files when flat view is off and I don't want to use copy queue.

How can I get this to work?

Multiple hotkeys/modifiers won't work with the drop events as they are designed to run on just the hotkey that's part of the event itself (Alt, Shift or Ctrl on their own).

If you need more than three types of drag & drop, adding things to the Drop Menu is the best way.

Is it possible to add more modifiers to drag&drop events list in file types dialog? There are more than 3 possibilities. Or do you think that it would be rarely used?

By the way, I always thought that when copy operation is triggered by drag&drop event, folder structure is never recreated (regardless of what you choose in preferences). But this doesn't happen to be true. I tried to test it a little bit and what I got was confusing. I dragged&dropped a file between folders in flat view and the result depends on whether I moved file within the same DO lister or moved it to another DO window. I just dragged&dropped them without any modifier keys and the action is just "copy MOVEWHENSAME" (I set in preferences to recreate structure when copying files). I recorded a video for you to see how it works. Is it intentional behavior or some kind of bug?

DOpus recreating structure.zip (1.25 MB)

What happens when you copy/move out of flat view depends on the setting in Prefs / File Operations. By default it asks if you want the structure recreated or not but you may have it configured to do it without prompting.

I mean... is it normal that structure is recreated when I drag&drop to another DOpus window, but files are copied to the same folder when drag&dropped within the same lister, as shown in the movie I made?

Yes, that looks normal to me. An unusual thing to do, but both behaviours make sense to me and if you configure Opus back to the default of asking what you want to happen when dragging between file displays then you'll be able to choose the behaviour.