I thank you for your interest in my article. Your viewpoint is that a standardized effect size can be useful when scale of the measure may be unfamiliar to many readers. This argument has been raised by several researchers, and it is also discussed in some of the references in my article.
When a scale measure may be unfamiliar to many readers, I think the author ought to aid the readers in interpreting the effect size. But I am not convinced that a standardized effect size is the way to go. Rather, I would report what is regarded as clinically relevant. For example, in (1) we report a randomized controlled trial comparing two treatment pathways for hip fractures. The primary outcome was mobility four months after surgery, measured by the screening test Short Physical Performance Battery (SPPB). This is a scale ranging from 0 to 12 points, where higher values indicate better mobility. An effect size of 1.0 points on this scale is regarded as a substantial meaningful change, and 0.5 is regarded as a small meaningful change (1). The reported effect size of 0.76 points in favor of the new treatment pathway can thus be regarded as clinically relevant.
We did not report the standardized effect size, which would be the effect size divided by the standard deviation in the control group, in this case 0.76/3.12 = 0.24. Such a standardized effect size would be regarded as a small effect. If the same effect size of 0.76 had been found in a study of more homogeneous patients, say with standard deviation 1.55, the standardized effect size would be 0.49, typically regarded as moderate. But the clinical relevance would be exactly the same.
Regarding your last point, I completely agree that effect sizes should be reported with some uncertainty measure, usually confidence intervals. But I generally prefer the effect size on the original scale, rather than a standardized effect size.
1. Prestmo A, Hagen G, Sletvold O et al. Comprehensive geriatric care for patients with hip fractures: a prospective, randomised, controlled trial. Lancet 2015; 385: 1623-33.