All in my opinion, others will differ:
Reese/Drawtite set up guidelines are to get you started—what is most important is where you end up, and my opinion applies to where I think that you should end up (again, others will differ). Final setup is almost always a try and tweak process of many modified settings.
The old adage of setting weight distribution so that both front and rear of the TV drop applies more to your dad’s station wagon than it does to current pickups and large SUVs. These vehicles set high in the rear and are designed to drop under load. Both Ford and Chevy at times recently have cautioned to not run the front of the tow vehicle lower under load than when empty—don’t know if RAM has ever made that statement. To me, the logical reason is that the goal should be to keep about the same weight on the front axle when hitched up with WD as it has when no load is attached for best possible steering. Therefore I would adjust WD so the front stays close to the same or slightly up after WD is applied. However, if the rear of the TV drops way too much, one may wish to adjust WD to transfer weight from the rear to the front being careful to stay within the TV manufacturer’s guidelines. The OP has no need to put more weight on the front, and maybe less would work better.
In Reese/Drawtite land one must end up with at least 5 chain links under tension (more is better) to allow room for the components to move without binding in a turn. While I have no experience setting up the TwinCam (but, will be doing it with my son shortly), I suspect that even many more than 5 links under tension may be necessary for good operation of the TwinCam. The head must be tilted to increase the number of links.
While measuring the tire to fender gap is the theoretical perfect way to measure weight on the axles, I find it WAY easier to measure the front and rear bumper in the center to the nearest 1/16”. If the back drops a few inches and the weight on the front axle is the same then the front bumper will come up slightly—my goal in setting WD is to have the front bumper rise 1/16” to 3/16”. That will cause the front axle to have very close to same weight as the factory designed it running empty. Once that is achieved, I check the rear TV droop to see if I can live with it. The trailer itself should be riding level or slightly down in front. The ONLY way that trailer level should be changed is by adjusting the ball mount up and down on the shank. Once the shank position is adjusted, the WD may need to be adjusted again.
