Anytime you use a non-native carrier, getting iMessage and FaceTime activated for your cell number is dicey. They send out an authorization code which un-official carriers interpret as an international SMS. So, getting iMessage and FaceTime to work with your cellular phone # is very difficult on un-official carriers. However, they will both work with an email with no issues.
By the way, this is an issue no matter how you unlock, sim interposer, SAM, Ultrasn0w, etc.