>>>>>>>>>>>>>> I've had students crossover from ITF styles and most of my time is spent changing them not just to Kukki-Taekwondo style, but correcting basic mistakes that they really should not be making at their grades.
One of my crossover students parents (recent crossover, a month or two) commented that after switching to my club she went back to her old club for a session, just to be sure that she definitely wanted to move rather than just be blinded by the excitement of something new. Her old instructor was doing pattern practice (hyung?) and asked her to do her pattern for her next belt. She reminded him that she hadn't been taught it yet and his response was "So, look it up on the internet and learn it".
Honestly, I could feel my blood boil when I heard that! The internet is a great tool, but it's not a substitute for decent martial arts instruction..................