I used net carbs and 40g limit, it’s individual, my approach worked when my goal was only ketosis and fat adaptation. 20g is good for most but not for all and many people experience total carbs work better for them. I am below 20g total nowadays when I do keto but it’s a side effect of carnivore(-ish) It’s definitely way better for me but lowering my carbs were only one (though needed) change.
<20g net carbs is good as a starting point. I would have done that if that would have been realistic. I made a gamble and got lucky. But even I had to go lower for success.
I definitely won’t, I experienced it (my previous diet was low-carb but that’s not the point though that was the reason I kept eating exactly the same amount of calories. I ate more on high-carb and not just a bit, I very much overate there because carbs made me hungry. I probably would gain on keto if I ate that much but I can’t know and I can’t do that anyway).
There are other opinions and experiences. But many people on this forum need to control the amount. Many people automatically eat less on keto (others not but interesting things happen. the human body is complex and the calories don’t act in it the same as in a caloriemeter) but not everyone. Some of us have the typical hunger and satiation change later, not right in ketosis but when fat-adapted. But fat adaptation and extreme low carb together, that was the real game changer… I still don’t lose fat, it’s me but I feel better, eat a bit less, move more (yay! I can’t feel right without proper activity) and it will happen. And I would lose if I had more to lose, I didn’t even need keto for that, just low-carb.
Intermittent ketosis? Is it a term? Hmmm… It must be individual. I did on/off keto for years because I couldn’t find my sweet spot yet and I felt the same on/off keto, keto was just less comfortable. But it was a temporal, not ideal keto for me, I had to change my food choices there.
And my off times were low-carb, no heavily processed food, no added sugar…etc. I had lots of rules. No way I ever go back to my very old woe… I left it for good when I went low-carb.
So no, don’t do “normal”. What people call normal is very unhealthy for them, usually.
And I am not extremely sensitive to carbs, I could eat much sugar without serious problems (like feeling bloated or having a stomachache) if I barely had carbs for a while - but a whole week eating, like, 100g carbs, that’s almost guaranteed carb poisoning to me. I can’t have any idea about your body but a week “normal” sounds very much after your body doing its business after 3 weeks in ketosis… It must be a shock. It can adapt, our body is awesome (well it depends how damaged) but it deserves better.
I really understand the charm of carbs, there is a reason I went off keto all the time when I had my original, not good enough style - but you can learn to “need” only a little. Keto food is great if you choose well to begin with. We still may desire different things and even indulge ourselves if we are that type (it’s a bad idea for people who get triggered or get sick then) but it should be in moderation, not very often, not for long… At least for us who actually feels better on keto and it’s probably quite common. If you can’t do keto all the time or you can but it’s a huge sacrifice and you are fine on a carbier diet too… Well, do whatever feels right but I don’t think you should decide on whole carby weeks… But you should know what is best for you - or not but experiments are useful…
You might not even want a carby week after 3 keto weeks. One can change a lot and keto food is nice. I am a hedonist, getting joy out of things (like eating) is very basic to me - but I am just fine without eating every tasty things that exist near me. I want good food and I get it even on carnivore, carbs are overrated. If I really want some carbs, I eat them but excessively for a week? I didn’t “need” it even as a beginner. Well I never jumped into keto from high-carb either, that would have been hell to me. So do what you think is best but think of the possibility that you indulge yourself and you stay lowish-carb. And just because you refuse to give up some carbier item, it doesn’t mean you must go off keto, it depends. If you are fine with tiny amounts, your chances are better