Modal operation information/key modifier on status bar and on top of an editor

Does anybody know the reason why some information is placed on the status bar and some are on top of the editor when using a modal operator? What are the “requirements” for some lines to be placed on the top or the bottom?

  • In the move/transform operation, the information is placed on top and the bottom
  • on loop cut and slide the initial number of loops is placed on the bottom, while the slide adjustment is placed on top.
  • on knife operation, the information is placed only on the bottom.
  • on Inset operation, the information is placed only on the top.
  • etc

The only thing i notice is, that when the modal operator needs to show a mouse modifier, it’ll use the bottom/status bar, while the top bar is used when there is only a key modifier present or when it only shows a string/text information.