Found this in a Q&A session with the THST and representatives from the club.But they're watching, so
Q: It's key that the desire for safe standing is stressed in the single tier stand, so that we can easily respond to any potential change in legislation. As seen in Dortmund's stadium, this would truly add an ever greater USP to the current stadium plans.
A: The single South tier has been designed with safe standing in mind, with the ability to introduce rail seating in the tier should legislation change.