In my personal opinion I would say Lean Xtreme is not worth taking on keto. One of the biggest points of keto is to increase your insulin sensitivity so when you have a carb up it is mainly stored as glycogen. Your cortisol levels may be higher, but regularly you have no carbs coming in. I think Lean Xtreme would work better for someone on a carb cycling diet since there is always a carb intake present.
I do think the ECA stack will help on a keto though. Not only will it help rev the metabolism up but also give you extra energy for your training and so forth.
My 2 cents.