This is my first post, and I hope it is helpful. And also, thanks to the developers for their hard work.
Currently, it seems that the numlocked keys on the number pad cannot be used as shortcuts. Even if the numlock key is pressed, the numpad key is registered as if the numlock key is not pressed. So you cannot assign the numpad arrow key, which is the numpad 4 key with the numlock on.
An example scenario where this would be useful:
With a tablet pc that does not have number pad, a separate number pad can be bought, and put on the left side, for example, and the left and right arrow keys on the number pad (with numlock key pressed to on) can then be assigned to frame offset, and used with the left hand while the right hand uses a pen to make changes to the animation. And once that function is no longer required the numlock key can be released and viewport view keys (perspective/orthographic) can be used. So two sets of shortcuts, with numlock and without numlock.
Also, by allowing the numlocked keys to be additional options for shortcuts, we can have atleast nine additional keys to use as shortcuts on the portable number pad, or even the integrated number pad.