You know what's cool about the internet? People's actual words are written, and can be copied and pasted. As here, where you wrote:

"Feel free to try adding muscle while in ketosis and not in a calorie surplus - you will be wasting your time."

Wasting your time. Which means not possible. Because if it were possible, you wouldn't be wasting your time.

If I put on 10 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on 9 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on 8 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on 7 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on 6 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on 5 pounds of muscle in ketosis while eating a calorie deficit - you're wrong.

If I put on even 1 pound of muscle in ketosis while eating a calorie deficit - you're wrong.

Put a fork in it, son - your theory's done. And when something's done, I don't mess with it anymore. If you do, you'll be talkin' to the hand. Done is DONE.