Alt (Essentially the Meta key in Windows) plus an arrow key should have some sort of function bound to it.
For designations menu:
move the cursor to the end of the 'type' of square you are over (either wall, floor/designated for mining, or open space/designated for channeling) in that direction, such that using it in a room brings you to the edge of the room, using it between two rooms would essentially make it easier to highlight a hallway, when in mining designation mode. In traffic designation mode, it should do the same, except with traffic designations. In the other designation modes it should do the same thing as mining designation mode, except it does not pay attention to designated squares.
It makes it a lot easier to navigate/designate large floor plans, e.g. designate a room here, there, there using standard shift-arrow and arrow. Using alt-arrow, quickly zoom around boundaries of rooms and construct hallways between them with far fewer keystrokes.
For other menu modes:
In view unit mode, it should go to the nearest unit in that direction. Same goes for view building mode, except for buildings. Same for look mode, except to the nearest non-hidden/non-forbidden (set by options menu) item.
Inspiration from emacs and other programs designed for text-only terminals.
Though I have made this suggestion before, seeing flow values vs. not seeing them should be able to be set from the in-game options menu.
That is all, I believe.