Disabling middle click on bottom of a clickpad / touchpad

The Thinkpad T480s has a "clickpad": a touchpad where (parts of) the touchpad itself is pressable instead of having physical dedicated buttons. Running X.org 7.7, there is a horizontal stripe at the bottom of the touchpad that acts as the mouse buttons 1, 2, and 3 (i.e. left, middle and right); basically it looks like this: +-----------------+ | | | | | | | | |11111 22222 33333| |11111 22222 33333| +-----------------+ How do I disable button 2 and reallocate that area to between buttons 1 and 3? I.e. I would like the following layout: +-----------------+ | | | | | | | | |11111111 33333333| |11111111 33333333| +-----------------+ **Note** this question is different from https://unix.stackexchange.com/q/326554/6706 since I am trying to do this in the context of XInput, not mtrack. Also, the hardware is not Synaptics. The hardware in question is identified by XInput as ⎡ Virtual core pointer id=2 [master pointer (3)] ⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)] ⎜ ↳ ETPS/2 Elantech Touchpad id=11 [slave pointer (2)] ⎜ ↳ ETPS/2 Elantech TrackPoint id=12 [slave pointer (2)]