If your doing a double bungy mod, actually there is a much simpler and better double bungy method that works way better than some others I have seen, and also prevents the AMA from any possibility of coming off (no hog rings necessary, just knots). Actually you can easily sit on the AMA without fear of it ever coming off or over stretching the bungy's.
Here is a pic of my setup, I've been using it for a while now and it is rock solid and easy to rig, just slip the cinch knots over the post, by doing it this way with the Hobie grey spectra rudder line (which is way over 300 lb test). You have room to add other stuff over the top of the post (I use those posts for everything (ie... including, tramps, ladders, holding spray skirts, etc). We use our TI for mostly snorkeling and scuba diving down in the keys, and often have 5-6 people all snorkeling or diving off the boat. Many like to sit on the AMA's, and the easiest way to get on board the TI is to climb on board over the AMA's. If you look at the small piece of spectra string to the right of each bungy, this prevents the AMA from stretching any more than an inch or two, then the spectra line tightens up (works just like your rudder up/down line does).
Of course you can do whatever you want to do, but I found this to be much easier, stronger and way more reliable, even if both bungy's break the AMA still cannot possibly come off. I call it the "RFM Consulting quintuplet reduncy bungy Retention And AMA pulloff Proof system for the betterment of mankind", or RFMCrap for short, ( LOL).
Took all of ten to fifteen minutes to make. You can get the Hobie Spectra string at any Hobie dealer or ACK for about $.30 cents a foot ( I use the stuff for everything ( tie all knots with cinch knots), plus most of us have this type of line just laying around.
I got the 1/4" marine shock cord at West Marine (not expensive), don't use cheap bungy cord from places like Walmart, it doesn't hold up very long. Only use black shock cord, it's impervious to the sun.
Of course if that's not what your doing (never mind), it didn't dawn on me that you might not be making double bungy mod until after I wrote all this crap.
Hope this helps