I’m doing ADF (40:8) right now, so I’m technically fasting 3.5 days a week, just passed a month and I’ve seen considerable gains. I aim for 3500-4000 calories in my eating window while eating lots of protein. I think as long as you’re eating good you should see some quality gains, best of luck!
There are some substances that are very important to muscle gain that you may run out of while fasting, stuff like L-Leucine. Its definitely possible, especially if you’re getting lots of protein on your feeding days. Just do research and keep your muscle goals in mind when you’re feeding, get some supplements where necessary. Good luck
You definitely can, up to a point. If you are losing weight eventually your body won’t have stores of energy to repair muscle. As long as you eat enough on your eating days, or have fat stores, it will work.