Bob is right that Reese recommends 5 links minimum. Many people confuse the links. That means 5 links under tension, not hanging loose.
I would increase the hitch head angle first. Adjusting the number of links under tension will affect the flatness of the trailer. You said it is level already, which is good. Fewer links (under tension) will raise the TT nose more than increasing the head angle. That might mean lowering the head by one set of holes, which also throws off the length of the arms for the cams over the lobs. That leads to even more adjusting.
Etrailer has a great video and installation/adjustment instructions. Obviously, you can skip the installation part, but the adjustment really helped when I changed my tire size on my last truck and really upset the RV towing. I disagree with the equal squat, or 1/2" front squat. Reese and most truck owners manuals recommend returning the front axle weight to the same as unhitched when using a WDH. Like your 3320 front axle weight should be the target.
I ended up with both my previous F150 and current 2500 Burb with full head tilt and 6-7 links under tension for my 1200 pound bars. Once adjusted correctly, I am comfortable towing well above the 65mph rating of the TT tires.