Did you turn the have the rotors machined? Are the shims properly sealed? Had that problem a few years ago after ensuring calipers and sensors were clean and good to go along with basically super glueing the shims still had excessive squealing. Rotors looked good no grooves which is why I felt turning them was not needed. After doing all I could decided to get rotors turned (wound up being clean up cuts not much metal removed) re installed problem was solved. I also advise going tp the search page for additional answers here, many have had the same problem.