Vegasears,
Having been a carpenter. I have the 97 UBC at my fingertips as that is what we used to use here. We may now be using the IBC I dont know as I have since moved on to a desk job. The nice thing about using steel studs for basement framing and a floating wall situation is they make a special track, the bottom section ramsets to the floor and the top section gets screwed into the studs. If I remember correctly there is a spring mechanism between the two plates. Having never used this piticular construction method. I have always framed in wood for basement construction except for steel soffits.
It is not about the fact that it is a non-bearing wall. The float is required because of expansive soils. It allows the concrete floor to move up and down without basement walls stressing the house above them.
Michael