I say my usual: it’s very individual. @Mavro may be right about it’s different when one is fat adapted - I can’t really know as I stuck to keto until my fat adaptation changes, it was important for me. But I can say fat adaptation doesn’t mean we don’t get back cravings. It probably helps a lot but some carby food items are more powerful than others. It really matters what and how much we eat on our off days. Having an off day is usually no problem for me BUT some items are hard drugs and I am familiar with chaos but they do it at some too high level… It’s probably mostly mental, we have our weaknesses and we should be abstainers regarding some stuff. It’s true even on keto as keto allows every kinds of food in tiny amounts but they may still cause problems and not only for 1-2 days after consuming it.
And if we finally forgot about some trigger food but bring it back… And let’s say, we cook that food multiple times a week for our family members… Or just seeing it all the time in the kitchen… I can imagine that makes our near future way harder. Not necessarily, if I really cut ties with something, it can’t easily come back but there are all the other items… And why to make our life harder for a while if I have the power not to eat the dangerous item (or in dangerous amounts)? (If we can’t resist, that’s another thing, we still have options then, of course. I train myself and figure out things to avoid temptation. As I don’t resist it. Everyone should figure out these things for themselves. I know how much I can safely relax my ways under which circumstances and where dangers lurk. I don’t always act accordingly but I know it. If I manage to run back to carnivore, my eating problems usually cease to exist but the chance for it is slim if I went too far but not far enough to make myself sick… So I better think before I go off and being forced to it usually means I was too optimistic about the options somewhere far from my house. I always must bring food with me if I leave the house for long, even if there are 20 chicken thighs waiting for me. It was my latest lesson. It’s amazing how things are able to ally against us. I couldn’t buy food the next day either as it was a national holiday. There are always ways for the determined me but I was in a different, not that determined state. I keep learning…)
I have my on/off times since ages and now I know it’s best to find the style where we just don’t feel like going off all the time. We don’t need physical and emotional rollercoasters, it’s not nice. It may took much time to arrive to our sweet spot but it’s great to find it. It can help tremendously with our control. I train myself to eat better since ages but carbs always interfered, even in ketosis. I couldn’t go very low until I stopped clinging to vegetables so I have no idea what would have happened on some average keto style but my newer carnivore-ish woe suddenly made things WAY easier.
We here know that just being in ketosis or just eating below 20g carbs, net or total doesn’t mean things get much better. Some people need tweaking to find there sweet spot. Too strict isn’t good, too relaxed either, some items may interfere with things, certain very keto foods can’t satiate us well…etc. No wonder problems arise, most of us aren’t super determined “strong” ones. I was determined once but it couldn’t stay forever especially that I got about zero noticeable benefits. Tweaking my woe was needed and now I need way less efforts to do my woe better. So sometimes we don’t need to use more willpower or sacrifice, we just need some change, not like it’s necessarily easy to see WHAT and how 
I am sure I am not the only one. It’s always a day for me. It’s my smallest unit, my body and mind works this way. I may have a carby meal but it must be very very late. If I eat carbs at noon, I will eat carbs at 3pm, 6pm, 9pm and maybe even at 2pm. I may decide not to (I actually did and tried) but it never will work. I don’t give up things easily but as years pass without a single success, I accept my limits.
If my carby meal isn’t very late, it must be a big OMAD meal not earlier than 3pm. But I need very much carbs and calories and sweets then to make sure I won’t eat another big carby meal after midnight.
I am all for a single off meal if it’s realistic for others, though. (I COULD do a carby lunch with not much carbs later if I wanted, it just would consume more willpower I want to use in a year regarding eating. I rather don’t eat lunch then, that’s way more enjoyable, probably healthier too. A well-fasted state is a more controlled state for me.)
(I still eat my dinner but I need a smaller one, usually). Because I overate so it’s not a good deal but still, it could be worse… It matters what we eat on carby days (and what exactly is “much”). But we are different too, of course, even from ourselves at different points of our journey.