My view is, it's different for different body proportions. When I was in my late teens I had a pretty flat upper body and weighed 135#. At that time KOPS might have worked for me, but I'll never know because now, 50 years later I'll probably never weigh 135# again. I did set my saddle to prevent "bad" saddle pressure and to keep from sliding forward. It was a Brooks Professional so I could not slide it back much, but I could raise the nose, at least coarsely. Now just shy of 70, I have BMI less than 30% (yayyy!) but I weigh about 195. My upper body has a lot more muscle and also a lot more torso fat. I now try to put my CG above the BB so that when I lift my body to ease over a bump it does not slide forward. I think this fore-aft condition also results in me being able to pedal well with my sitbones usually in contact with the saddle, hands near the hoods, with easy reach of the shift and brake controls, and most of my body pretty relaxed.In all my modern settings the knee position does not matter, but it's usually a few cm behind the KOPS position. Adjusting setback also affects effective saddle height, since if the saddle is level and moves back, the long edge of the triangle gets longer, so the saddle needs to be lowered a small amount.

I also reduce saddle height to prevent my hips from rocking side to side due to excessively reaching down to follow the descending pedal. It's kind of finicky to find where my leg needs to stretch to, without hip-rocking and without pressing too hard on the pedal at BDC - that extra pressure causes knee pain. The sweet spot is hard to find.

KOPS, as a rule, is far too simple, for my use. It means nothing for me.

My current dream weight is 155, kind of an arbitraty number, but if I reach that without losing muscle mass (i.e. strength) my power to weight will be pretty darn good and I should be able to actually do some mountain road rides, or maybe RAGBRAI. Lately I've dropped it from 209 to 194, and I think that was due to better eating and more usage of polarized three-zone training - it's easy to manage, adds tone to my whole body, increases my strength (better balancing in Yoga practices!) and my muscle mass shown on Ironman scale should be increasing the rate of fat consumption. 20 miles 2 weeks ago, 20 miles one week ago, and 25 miles last weekend. Training is a good thing. I need to look into more accurate setting of the three Seidel zone limits.

I can report back on the KOP thing when I reach 155#.