I don't think there's much use to be made of the track. On a two masted rig, the after sail can profitably be sheeted closer by hauling the traveller up to the weather side; but a single sail shouldn't need that.
The upper and lower sheet are useful, though. Since you have control over the twist, step one is to learn how much twist there should be, by adding telltales to both the upper and lower leech and the upper and lower luff. Adjusting the sheets to keep them all streaming nicely should be straightforward. But then, knowing how hard to sheet in when on the wind is a matter of knowing the boat, whether the sheets are double or single, so there's no off-the-boat guidance to offer.
But the most important advantage of double sheeting becomes obvious when deeply reefed. With a single sheet, way too much twist develops. With two sheets and two or more reefs, the lower sheet carries little or no load, and hangs slack, the upper sheet doing all the work. Thus, it's easier to keep the sail working efficiently when deeply reefed and working to windward, and I reckon that to be the chief benefit.