Hmm, I have no idea what it's for. I can really think of anything back there either.
Anyway, I have the same problems on all four of my stabilizer jacks that others have reported. The dealer is going to take a look at them on Friday and replace them as soon as they get authorization. Hopefully that will happen quick because we're leaving Saturday morning for our shakedown trip.
I got a few more things installed on the trailer...
ProPride 3P Hitch:

And exterior sewer hose storage. I did a lot of reading about different ways people built their sewer hose storage but had to come up with my own way that was super cheap ($6 for the 4" corrugated drain pipe, $10 for the drain cover) and super light.

I used industrial strength indoor/outdoor Velcro that is super strong and water proof. The picture below is the open end. I couldn't find something to use as a cover so I cut out some window screen mesh I had in the garage and used a bungee cord (the red ball) to fasten it: Easy on, easy off.
