I would like to be able to highlight (backlight?) hotbars when keyboard modifier keys are pressed (Shift, Ctrl, Alt, any mixture of all 3). The intent is to be able to provide better on-screen feedback of what modifier key I think I might be pressing.

It is not the intent to change/replace how hotbar keybinds are done. For example: a player would be freely allowed to assign Ctrl+6 to a slot on a hotbar that's hightlighted when Shift+Alt are pressed.

This visual feedback would be akin to how pressing LT/RT on a gamepad highlights the left/right side of the crossbar set the player can now perform. It would be nice if the slots/icons increased in size slightly like they do with the crossbar.

Configuration of the feature would be via a 2D grid of check boxes (not radio buttons) with hotbars along one axis and the 8 arrangements of modifier keys along the other axis. This is to allow a hotbar to be highlighted for more than one modifier key mixture. For example: a player could set hotbar 3 to be highlighted when nothing, Shift, or Shift+Ctrl are pressed, but not for the other 5 modifier key mixtures.

Alternate request: Allow me to "Switch to Hotbar #" via hold or toggle of modifier keys (again, like LT/RT can do for the crossbar).

Mostly, I think keyboard/keypad players should have UI features that exist for gamepad players.

Thank you.