That, in general, is the problem with testing NDL ascent profiles--too many options. The studies that claimed a benefit to deep stops on NDL dives suffered from the same problem--you added to the ascent time and found an improvement, but you did not show that the depth at which it was added was beneficial. Is it possible that adding that time to the shallow stop would have had an even greater benefit?Yes. It was measure of VGE, but the time chosen for the stop was arbitrary as best I can tell, and both of them showed a reduction in VGE, but is 5 minutes better than 3, is 10 better than 5? is 20ft better than 15? Those parameters were not tested.