I hope you've misread Sheldon's recommendation, because, if not it's plain wrong, and it may be part of the reason so many newer SS, IGH, and fixed gear riders are having so many problems.

The right advice is the same as it's been for a century. Chain drives (without tension idlers) must have a slack loop. That applies to ALL chain drive systems including bicycles, machinery and trucks. There doesn't need to be much slack, just enough slack to accommodate any eccentricity in the sprockets and ensue that the chain is never tight.

Chain drives have two loops, the power loop which is under the tension needed to transfer torque from one sprocket to the other, and the return loop whose sole purpose is to make the system endless. Tensioning the return loop (lower on a bicycle) only serves to increase the loads on all the components, and cause premature wear or failure. Here's a link to images of chain drive trucks. Note the visible sag in the lower loops.