I once requested this to Marble Man before he was banned.
But my request was different, I requested a hearing client that shows an outline of a player's body, vehicle, bot. through walls
and when they move, you "Hear" them by seeing the outline of their shape.And when player's attack with a weapon or chat, you can hear them. CAPS chat makes their outline even more visible, the further they are the more faded their outline is.. But it turns out he denied it claiming it was "Impossible for BL" and if he tried I would have to pay him.