Agreed.. I’ve had them touch and nothing happened.. right now I have a tubs Stella growing into a cornbread malenificent encrustation on a rock where I broke the frag off… I’ve been curious who will, kill who and so far nothing… the Stella has made its way all the way up to it and now growing around it with about 32’d In between each coral..Sometimes two acropora can grow next to each other without killing either. It is not necessarily grafted or becoming one (although that can also happen).