Sam,
What Jeff didn't tell you and their website doesn't tell you is that the setup they have on their website isn't the actual system they are using. They can't share all their secrets, actually I think they are just too lazy to update it.
Mike & Tripp and most well tuned boats run a "continuous" downhaul. I say it in quotes because on the infusion you can't have a true continuous because the line has to come apart to come off the mast base.
Tripp sews the end of the downhaul together every time they sail. To de-rig they have a leader line.
On my old infusion I tapered the end of down then tied a small stopper knot (single half hitch) and tied them together and taped them up a bit then pulled them into the middle of the system inside the beam.
You'll need about 45' for this system.
To look how to run the shockcord for a continuous system look up the AHPC rigging manual, http://www.2bsailing.eu/downloads/c2-owners-manual.pdf
Page 6.2.1
The blocks the blue shockcord runs through are attached/tied to the posts in the beams and the blocks they are tied to are free running. The block outside the beam is obviously for tying it to the trapeze.
Keep in mind the C2 has a true continuous system with a splice inside, this is where you have to improvise to have stitching or something like i mentioned above.
-Todd