Carb Cycling?

I have decided to lean out before I plan on trying to gain muscle/mass. I currently weigh 188-190 at 5’10, and am around 15-18% bodyfat. I recently have tapered down on my carbs and calories.

I calculated that it takes me around 3-3.1k calories to maintain 188-190 weight. I am aiming for around 12% bodyfat, and either around 178-180 lbs bodyweight. I have tapered down on my carbs and calories in the last four days, and am just confused as to where to go from here. I have been logging everything and have gone from consuming 150 to 100 to 20-30 g of carbs over the last 4 days, while increasing my healthy fats. I have been eating very clean and was curious as to how you guys carb cycle, as there’s many approaches.

I read “Research Approved Carb Cycling” by Mike Roussell, but what i was wondering was, why is it that on the low carb days for many of those plans, they still only consume around .15-.35 g/lb of fat? shouldn’t one consume more fat to make up for the decreased intake of carbs?