You can still fast with low bodyfat% but it will be harder versus someone who is obese. I wouldn’t go longer than 72 hours at a time though, and make sure to get enough electrolytes (read the sticky)
For hunger and cravings, it helps me if I start a fast already in dietary ketosis. That lowers hunger a lot in my experience. Cravings on the other hand are usually mental. Hell, sitting here I’m craving beer, that’s just par for the course