Game pad switching, merging, or re-arranging. Can i make the keyboard game pad 4?

I have a 1-4 split screen local co-op game. I want players to have the option of gamepad 1 being the keyboard, or of being a controller. The issue I have is unreal only allows for either gamepad 1 to be just the keyboard or the keyboard AND a controller. Never just a controller.

So if players have 3 controllers but want player 4 players with a keyboard as well then I can do that. Gamepad one is assigned to the keyboard by having skip assign on. But now if they decide they want to play 3 players with only controllers they can no as the build is set to only have the player use the keyboard.

If I build with skip assign off then those players with three controllers can never play 4 player mode as the keyboard will always be player 1 along with one of the gamepads.

If there was a node to toggle skip assign gamepad to player 1.

If I start with skip assign on and then somehow merge the player 1 and player 2 controllers when players chose to not use the keyboard.

If I could have skip assign on but then have the keyboard control player 5( a nonexistent player in the game) Then I could delete player 4 and have player 5 with keyboard control take his spot when players want keyboard control.

The issue: I do not know how to do any of these things to achieve these solutions and I don’t know if unreal even supports any of them. Anyone know how?

Basically, i need an adaptive controller switcher that allows players to either use 4 controller or 3 controllers and a keyboard.