Just a reminder - proper weight distribution to reduce instance of trailer sway ISN'T just limited to a target tongue weight of 10-15% of the tt weight. It's about intelligent loading of the trailer, and concentrating weight where your trailer is most properly equipped to deal with it.
The following video is invaluable to watch all the all way through:
You have to balance all forces, but it's best if that tongue weight comes from central massing, as opposed to dead weight located as far forward as possible.
Lots of people have seen videos like this, this one - however, is a LOT more sophisticated. I recommend you watch it all the way through. This one is a BRILLIANT demonstrator for weight, distribution, speed, slope, etc. Really a must-watch to show all the things that are missing from that "rear loading is bad" demos.
We now return you to your regularly scheduled forum.