My advice....if you are wanting a 3hr eating window, don't do it every day.
IF is "Intermittent Fasting" remember. Metabolic setbacks happen when you don't eat enough over a long period of time (days...weeks....not hours) or also train way too much (and never recover).
Start by using it 2-3x a week and go from there. Remember at the heart of it, it's just a "tool" to use in your lifestyle approach....not a diet plan. You can always change it up however you want later on once you know how your body is really responding to different training and eating approaches.
You may also do well with some carb cycling....lower carbs cardio days, a bit more pwo on workout days....or longer like 3-5 days low and 1-2 day smaller refeeds.....not absolutely necessary to lose weight, but it helps with many especially if you have no desire to measure out food from now on.