Anybody who has done keto and lost weight certainly does not say they had evergy on it. Those first couple weeks are terrible and you never quite have the energy you want. Thankfully it is a short term diet with specific targets in mind. Any positive effects after stopping keto are from the weight loss in general. Even keto diets recommend against a high saturated fat content but with keto your body is in a specific state that blunts the effects of a high saturated fat intake.
When you go off keto you cannot maintain the high saturated fat intake without measurable negative impacts.
Who says it? I had more energy on keto, except for one day (around a week after starting) that felt terrible and was fixed by drinking water with salt and potassium. Keto diets don't recommend against a high saturated fat content, only some do because of the common misconception that it is bad. There are no studies showing bad effects of saturated fat by itself. It's the carbs what causes the problem, fat only makes it worse.
When you go off keto you cannot maintain the high saturated fat intake without measurable negative impacts.