Mouse cursor relative to Dolphin main window instead of the game

I'm using Dolphin 5.0-11966, and I noticed something weird with the emulated Wiimote pointer.

I'm trying to use my mouse cursor as the Wiimote. I have the Dolphin window on the 1st screen (left), the fullscreen game on the 2nd screen (center), the 3rd screen (right) is empty.

I set Vertical offset, Total Yaw and Total Pitch to some values that get the Wii cursor close enough to my real mouse cursor. However, I can't properly calibrate the cursor. The calibration thing is relative to the main Dolphin window and doesn't let me set a different center point.

I'm calibrating the mouse once, and then I need to move the mouse and click on the left screen, on the Dolphin GUI, to move and click the in-game cursor on the center screen.
Then when I move the Dolphin GUI to the 3rd screen, I still need to move and click on the GUI to make the cursor move and click in-game.

Why is the cursor stuff relative to the Dolphin GUI window and not to the game? What's the point in doing that? Is there a setting I need to set to use a mouse as Wiimote cursor?

I could move the Dolphin GUI to the 2nd screen, in front of the fullscreen game, then calibrate the mouse, then just hide the Dolphin GUI behind the fullscreen game. But then I can't change Dolphin settings mid-game ...

Why are these settings even needed? Can't Dolphin just tell the game "hey, the cursor is at this position right now"?

Leseratte10