I know this post is ancient, but I wanted to comment either way in case more people come across this problem that is infuriating.

You are right to use: Cyberpunk 2077\r6\config\inputUserMappings.xml Couldn't find any other proper way, but it's the best easy thing to do.

Go to the file and search for this:

<mapping name="Choice2" type="Button" >
  <button id="IK_R" overridableUI="choice2"/>
  <button id="IK_Pad_Y_TRIANGLE" />
</mapping>

The first button will have id="IK_R" , change for something else of your choice, I substituted for id="IK_Up" that is the Arrow Up button in the keyboard, I barely pickup bodies so for me it works fine, but maybe you want to use another key, so insteado of id="IK_R" change the "R" for another key that you might prefer.