Thanks RTCIV,
It's been fun to follow along the progress of your trailer too. I have found much inspiration from the trailers I have seen on this forum.

The long hitch arm is to accommodate long loads like a surfboard or long kayak. I got the idea from a Canadian kayak trailer company called "Tony's Trailers." The long hitch arm allows you to carry a long load without the long load hitting you in the back. See this link for Tony's Trailers http://www.tonystrailers.com/kayak/

Below is a photo of my trailer carrying a tall load on the way back from a run to the nursery to pick up an Acacia tree.