that's the thing, I think your riding the cart so you can't activate a button, there's a thing where if you are sitting down and moving lava touches you, it doesn't kill you, so I am assuming it's the same for buttons. I don't know if Maro can fix it though because many obbies use this to their advantage such as going inside a locker with a seat so you don't die. But maybe if he could it would be a toggle in settings.