I can only unbind the suicide key for a brief period of time through the ?-1 menu. It persists through a save but resets to normal after I reboot the client. Keymap.txt in data isn’t doing anything for me. I’m stumped.
Workaround for the time being is to rebind the key to an Alt combination, like ALT-222
I can confirm the automatic ‘rebinding’ of the suicide key if you unbind it, happens when the game is closed and restarted, but not if you load->unbind->save->reload without closing the game.