Great write up!  It's actually kind of fun to play with isn't it?  I've been carrying one of these for years, and I have a hard time going out without it now.  

One addition that I have made to my sled is a 10-meter length of 6mm cordelette.  I don't mind carrying 10-meters of thin cord, since I feel it can serve lots of functions.  In practicing with the sled, I like the piece of mind that comes when I increase the strength of the sled while pulling pulled on from one end.  

I put an eight-on-a-bite at the mid-way point of the cord.  Then I clove-hitch the cord to the "front" stretcher bars so I have a triangle to pull on.  Then the cord goes back to the opposite binding (opposite from the tip it started at) and then back to the tail at the same side it originated.  Before I fasten it to the tail, I put an overhand-on-a-bite in the cord, then it goes around the back stretcher bar, through the overhand loop, and pulled to create a lot of tension.  This can actually flex the ski, which I think is a good thing.  I fasten this with another clove-hitch on the rear stretcher bars.  I run the remaining cord back and create a loop.  

This makes it so I have a solid attachment point for a rope at both ends of the sled.  It also makes it so that as I pull in one direction, some of the load is actually absorbed by the bars at the opposite end.  It gets pulled together, rather than apart.  

With this set up I have never had one pull apart, even while lowering down 40-degree slopes.

I hope this is helpful. 

Super helpful and something I would not have thought of. I followed that description but I am sure many readers would be scratching their head - perhaps the next time you are using the sled you could take a quick picture for everyone to see exactly what you mean?

It would be a good visual for all and I have heard a picture is worth a thousand words.

Thanks for the feedback and advice.