You can do whatever suits you. Not eating at all, eating once, eating in a bigger window… ALL may work, it depends on the person 
A 4 hour eating window is normal to me (even if I often have a bigger one but I rarely need it, I am just that “undisciplined” and sometimes carni satiation is too “good” and I need more meals) so I wouldn’t change anything special on the leftover days… But I usually am good with bigger meals…
I don’t know what people consider “feasting”. I definitely should do my best to avoid “feasting”. Eating as little as possible and hoping for not overeating is my ideal attitude but it’s me. Feasting sounds serious overeating to me (or normal eating with a wrong label) but again, it’s me… What is barely eating to me may be eating until bursting point and force-feeding for some others…
I don’t even know how much you eat in your 4 hours. Little? Just enough for your goals? Much?
It’s a pretty important factor in deciding how you should eat on the other days.
I did some 40-48 hour fasts and one 120 hour long one. I never ever got energy kick from fasting, IF, keto or anything else. It’s not a guaranteed thing. I am a low energy person, it seems though I haven’t give it up yet…