—: Your idea would work similarly to mine, but I think it would also encounter the same problem.
I think the problem is that the weapon wheel is probably on its own layer with a (0,0) parallax, right? So unless you're in the very top-left of the map, the mouse is actually really far away from the wheel's center, and any movement only means a tiny change in angle.
Meanwhile, looking at absolute x and y, it seems like that refers to the mouse position for the entire screen, not just your game's window. Possibly not a problem once you port to mobile?
So a potential workaround: you could use (mouse.x, mouse.y), set the weapon wheel's layer to a (100,100) parallax, then set the wheel's position to (scrollx,scrolly) every tick. It does make the rotation work correctly. However, you would have to put your onscreen buttons in a separate layer or move them every tick as well. This method also makes the weapon wheel look a bit jumpy when it repositions, but it'll only be visible when the timescale is very low, so it might not be noticeable.
If you want to track the mouse from a layer that has parallax, that's what LayerToCanvas and CanvasToLayer is for
You can move/relate things on different layers with different parallax values using these expressions
~Sol