tl;dr : will a carbon stem accomplish vibration absorption a la softride stems?

My setup is pretty rough on the rider (me). I do my brevets on a Xootr Swift, 20" wheels, aluminum fork, stem, handlebar. Since all the other components are so harsh, I do use cushy 50mm slicks (70psi) for vibration absorption but I'm not sure what that achieves. I feel like I could get more comfortable by somehow reducing handlebar vibration. Perhaps if I could reduce handlebar vibration elsewhere I could put on the Continental 1.3 tires I bought last year.

If I swap out the aluminum stem to carbon, will I achieve good vibration absorption? Will the vibration absorption be on par with the cushy tires I use? I cannot switch out the handlebars since I use trekking bars and I haven't found those in carbon.

Just looking to get more comfortable and hopefully faster.