Actually, we race in the PNW and have our boat set up so that the downhaul exits the beam, runs back to the shroud, through a block and then to the downhaul purchase system.
The norm now, on most of the pro set ups, is to have the downhaul exit the beam and run through a small single block on the crews trapeze loop and back to the cleat. This has the downhaul come out with the crew so it's quick and easy to adjust for either member.
You need to set up a reverse 2:1 and continuous line inside the beam for the line so that there is enough length and take up. I don't think any of the manufactures do this as standard but I can send you a PDF of the set-up if you want but the lengths will be different as there for the CAP.
