The razerkbd hid driver for Razer keyboards exposes two devices

razerkbd 0003:1532:022A.0003: input: USB HID v1.11 Keyboard [Razer Razer Cynosa Chroma] on usb-0000:00:1d.2-2/input1 ... razerkbd 0003:1532:022A.0004: input: USB HID v1.11 Mouse [Razer Razer Cynosa Chroma] on usb-0000:00:1d.2-2/input2 

Each of these being later on associated to input events and registered by the X11 server (xorg-server-21.1.4)

XINPUT: Adding extended input device "Razer Razer Cynosa Chroma" (type: KEYBOARD, id 10) ... XINPUT: Adding extended input device "Razer Razer Cynosa Chroma" (type: MOUSE, id 11) 

Be aware that the physical device is nothing but a standard PC_105 keyboard only. I mean no physical mouse/trackpad/touchpad device actually exists.
When whatever key is depressed, the input event associated to the keyboard will echo the associated (sequence of) character(s) while simultaneously, the input event associated to the mouse will echo a corresponding mouse event.

I sometimes would like to use this device as a mouse (in addition to / instead of my standard "real" USB mouse) under my DE (kde-plasma 5.25) but it is unfortunately not listed in the system settings utility as whatever sort of input device.

How can I workaround this ?