There’s a very major caveat of jumping off keto abruptly (having a cheat day): https://www.everydayhealth.com/ketogenic-diet/cheat-day-on-k...

Sudden jump off keto may cause inflammatory damage to the endothelium of your blood vessels, and while in that one study, effects had been “transient”, I wouldn’t risk cheat days without a very gradual reintroduction of carbs, and surely not repeated cheat days. (My personal fat diabetic ass says it had a lifetime of carbs, though, so that’s not happening for me until at least 20 kg later.)

I know it’s just one study, but I would rather be safe than sorry until we know more. Case in point: the study subjects were all young and healthy, and most people who really need to go very low carb are not.