Don't really know what to say here... do you do that much driving that you get aches if you can't rest your foot on it as you say? No throttle cable, the stiffness would be controlled from the pedal assembly alone. Maybe you can open it up and find a way to make it stiffer, but that's uncharted ground because nobody has cared enough to do anything like that. I really can't say anything apart from get used to it. Never seen this before.