I am using the lowest pressure I can manage without bashing the rims on the ground. Yes, the tires are tubeless. If I go any lower than 35psi, I get rim dings. I weight 160 pounds.

A suspension stem does nothing for the rear wheel. My hands and wrists are fine because the bike fits. I could fit a much larger tire in the front but that is not the problem. I larger front tire would only encourage me to let the front wheel write checks that the rear can't cash, so to speak.
A larger rear tire would help, which is why I want to modify the frame.