I understand that there might be people who aren't incorporating the Sine Wave movement as they should in TKD and this can distort it's effectiveness.

Are you aware of any scientific studies specific to ITF TKD that show the Sine Wave, when used with other elements as you say, creates a more powerful punch? The reason I ask is that I've read about the science behind the Sine Wave in TKD but I've never come across actual studies that show that Sine Wave movement combined with other elements you mention allows a person to generate more power than they would by any other punching method.
"Let your food be your medicine, and your medicine be your food" Hippocrates.