O000hh. That does not cut it! CFB is not happy. Assertions without data, Really? I think you mean that the data is equivocal so you best not get into a linking match or an argument over what data is reliable and thus trash the thread. I'd accept that argument.

To the OP - run the same width tires front and rear, run them somewhere in the tire's stated pressure range. I'd also say don't run a wide tire on a narrow rim, especially a front tire, and especially an underinflated front tire. Worry more about safety than bar vibration. If your hands are uncomfortable, you probably have too much weight on them and not enough reach. With a good fit, your hands go up and down a tiny bit on rough roads, but so what.

Personally, on a 20 y.o. carbon bike, aluminum bars, I run 23 mm front and back, 80 psi front, 100 psi rear, and weigh 146. I have 23 mm outside deep alu rims to almost match the tires and CX-Ray spokes. I don't have any particular problem riding rough roads and never wish I had wider tires. I don't ride gravel if I can help it, though smooth dirt and hardpack are not a problem. My setup is noticeably faster than most.