Look, if we're going to make major life changes on the basis of this one study, you've missed the opportunity for an all-chocolate diet.
Does it have to be dark chocolate?
Eat more than a few tablespoons of any edible oil in one sitting and you'll definitely feel a difference.
Edit: using only added coconut oil in cooking is, upon reflection, a more probable interpretation. Sorry.
Edit: you added your edit while I was writing my comment :)
You can mix it in with things like coffee and shakes, easy way to get it.
https://raypeat.com/articles/articles/unsaturated-oils.shtml
Basically, any combination of coconut oil in your diet that isn't 100% coconut oil will lead to calorie gain.
What difference will I feel that couldn't be explained simply by my expectation that I would feel different?
The truth is that our stomach has a hard time digesting a sudden influx of MCT. Adding a large amount of MCT to a diet previously free of MCT will cause nausea. And that short term nausea is largely the cause of any "weightloss" seen by MCT. The studies that study MCT and show weightloss are all short term studies, and not the 6-12 month study you really need for weightloss.
In short, you'll feel a difference because coconut oil upsets your stomach. Not because it's a non-animal fat. Hell, we use sesame, peanut, canola, and olive oils all the time. Replace all your dietary fat with canola oil or olive oil and you'll not notice. Will probably have health benefits because of the reduction in saturated fats.
Coconut oil is mainly comprised of saturated fatty acids. Its closer to butter, not the refined PUFA oils.
Consuming anything to excess is gonna mess up your system, water included.