Oops I didn't realize I didn't respond to your questions.
By the "front left AKA brace," do you mean the cross bar that goes clear across the hull?
Yes the bar that goes across the hull, which is attached by brackets on each end to the hull, and in the center (where the sail is). I run the rope in front of the left brace, behind the big bracket in the center, then around front of the right brace. It is out of the way of everything like this. I actually leave the rope wound through there when I break the boat down, and just throw the ends of the rope (with the stainless clips) into the mesh storage pouches for storage. It takes all of 3 seconds to clip onto the AMA.
And then, do you tie the line off on both the left and right AKA braces (or left and right sides of the crossbar), or just run it around the brace and tie it only to the AMAs? Would it work just as well to use 2 shorter lines: one from left ama to left brace, and one from right ama to right brace? Thanks,
The rope is not tied anywhere, it just slips around the left and right braces. It is of course clipped with stainless clips on the ends to the AMA (as shown in the pic). Of course you could have two shorter ropes, just tied to the left and right outer AKA braces, it would serve the same purpose. I just thought to use just a loose rope initially that could be stowed in my sail bag along with my other misc ropes and sails in the garage. But after the first couple times out I decided to just leave it on the hull to save rigging time, it's been there ever since.
To test it out, just unhook the AKA brace and try to push the AMA back and in, using the stretchy nylon rope it pushes in just a little then springs back out, so if you were to hit a dock, damage will still be unlikely, trust me I've banged into bunches of stuff and sheared off many nylon bolts, but never any other damage (knock on polyethylene for luck).
I get into some pretty rough conditions at times, and have never had an AMA fold in, which would be your worst nightmare in really rough conditions. I have however sheared off at least a half a dozen shear bolts. With 260 sq ft of sail my TI really flies when I have good wind.
As a side benefit, the rope keeps the AMA's from bouncing all over the place and making a lot of noise (not planned, but hey it works)
Here is a pic of the safety rope in place, I just store the rope with the hull, and snap the clips on when putting the AMA's on.