Multi-select Subdocuments in Doctree by click+drag or shift-click

Usually there are a few ways to multiselect files on computers:

1. ctrl+click or cmd+click multiselect files one by one.
2. shift+click multiselect files in bulk
3. click+drag also multiselect files.

I often have to edit hundreds of subdocs (e.g. add to database, delete, move, etc), hence click+drag and shift+click are my go-to methods for multiselect.

However, shift+click doesn't work. I suspect it has something to do with being assigned to open below tab command by default and it is not configurable in keymap settings.

Question:

1. Is there any other way to quickly multiselect docs/subdocs?
2. Is there any way to remove shift+click from open below tab command?