As long as shock cord is the big soft wet kiss that everyone tolerates, Warbonnetguy is certainly correct that splicing, having conversation with customers about WHERE the shock cord should go, etc, are all needless complications.
Then there is he current method of setting the UQ. Pull it up tight, so it actually lifting the entire hammock up with hammock empty. Then get in, and release tension until the UQ just touches, and is no longer compressed.
Now, this is like torquing the bolt until it breaks, and then backing off 1/2 turn. Except, with shock cord, nothing breaks. Change out to less than 10 feet of play, as with current full-channel/ rail systems, and users expecting all that play could very well break the cord.
I wouldn't doubt that Warbonnet's engineered Yeti, a shaped partial UQ with gaskets on the sides (and therefore I presume a lower-pressure hollow in the center of them) works best with whatever system of tensions he has developed. At least is is described as cradling the torso and, I think, keeping it cradled as the torso shifts in the hammock. That requires a compliant suspension, I think.
But, for a full-length UQ, I cannot see the advantages of sometimes getting back in the hmmck in the dark of night and realizing that there was so much play in the shock cord that the UQ is hanging uselessly, a folded taco, entirely on one side of the hmmck. Seems to be tolerated by users asking not what the weight of the whole UQ system is, but what the weight of the UQ w/o the suspension. So, the suspension gets a pass.
I have further questions about whether soft, sloppy systems aren't responsible for the attraction of complete socks, because the sloppy shock cord misdirects attention from major convection losses of bad sealing, but that's for another thread.