Мыша

Наверное, не совсем то, что вам требуется, но...

man 4 evdev
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Option "ButtonMapping" "string"
Sets the button mapping for this device. The mapping is a space-separated list of button mappings that correspond in order to the physical buttons on the device (i.e. the first number is the mapping for button 1, etc.). The default mapping is "1 2 3 ... 32". A mapping of 0 deactivates the button. Multiple buttons can have the same  mapping.   For  example,  a  left-handed  mouse  with  deactivated  scroll-wheel  would  use  a mapping of "3 2 1 0 0". Invalid mappings are ignored and the default mapping is used. Buttons not specified in the user's mapping use the default mapping.
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То есть в вашем случае (замена средней и правой кнопки местами) это должно выглядеть примерно так:

Option "ButtonMapping" "1 3 2"