This is a patch for the default keymap in Blender.
It relates to the Dopesheet, Timeline, Graph Editor, NLA and Sequencer
Currently, in these editors, dragging outside of your selections does nothing.
This patch makes it so dragging outside the selection does a box select operation, which is consistent with how the Node Editor works, as well as the 3D View, if you use the gizmo overlays.
This is ported from the Industry Compatible keymap which is where I found the solution.
- More consistent with the Node editor, which already works this way
- More consistent with 3D View and UV Editor which allows box selecting by default
- You can still click and drag to transform items, just like in the Node Editor