Actually, I have pulled the sender out and I did see the little cylinder mechanism on the bottom. The sender, or any of its components, should never be dirty inside the gas tank because all that stuff is always swimming in gasoline. I think they replaced the bottom float with that little cylinder, which may actually have variable monitoring capabilities.
Here is how I can prove this:
A regular fillament bulb that sits in that little fuel graphic box will actually take above a certain voltage to turn on. On the other hand, an advanced LED bulb will work with any voltage applied to it. Replace that bulb with an LED and you will see that when you start the truck the LED will light up, which means that there is some voltage there while the truck is running and it will get brighter if you start to get low on fuel. A regular bulb will only start to get brighter after a certain voltage is applied to it but not when there is enough fuel in the tank.
I think this calls for some more experimentation!