I respectfully disagree, I think keto and IF work well together. Think about it, on keto your body breaks fat down into ketones to use as its main source of energy.
So when in a fasted state, while in ketotis, with no food in your belly, your body has no other option but to breakdown bodyfat into ketones to use as energy. I believe this is good, I have tried this approach with good results, not leangains style IF more eat stop eat style (24 hour fasts)