I just opened an email from Schluter this morning with the new commercial steam shower specification. What a day.
As it turns out Schluter will be selling finally the Kerdi DS version here in Canada. Kerdi DS is like Kerdi but thicker.
Kerdi DS or Kerdi Board will be required in steam showers for high use commercial type projects.
I believe the Kerdi DS is about 21 mil thick so it will be very close in thickness to Noble Companies Wall Seal membrane. Noble Companies Noble Seal TS and SIS is a 30 mil product. Regular Kerdi is only 8 mil.
I'll ask permission to post the detail here.