Help me out

My 12 week baby girl has a tongue/lip tie. She spends all her wake time attempting to eat, until she gets so tired she passes out. She is gaining well but only takes in very small amounts, so she doesn't sleep well. Her pediatrician recommended another doctor to do the procedure, but said that doctor will want to laser her tongue and lip ties and NOT TO. He said ONLY revise the tongue tie and leave the lip tie alone. I'm so confused! Has anyone else revised only a tongue tie and had improvement with their baby's eating?