The question was if you can put on muscle with keto, not if you loose muscle. I agree that you should be able to retain, but it's quite difficult to add mass when carb depleted. Great for show prep and fat asses, otherwise avoid more often than not.
You will have more energy with high fats! Have a refeed once a week... Of course all of this
Is for those who want to become shredded... Then you can introduce carbs slowly at 50g per week.. Do some reading on it
It's good info and another tool to use! and yes to your question about putting on muscle if you add gear. Go to the redditt forum you will get all the answers! Take care Goodluck