Twice, other than that no. In most behavioral programming interviews I haven't been structured in my answers as being structured came a bit later when I was also applying for consultancies. I was a lot tougher to follow when I wasn't structured.
When I was structured I did use a variation the STAR method when they expected me to. Having a method like that makes things quicker to go through, as long as you make it your own and own it. I adapted the framework a bit by swapping the T (Task) for P (Problem) as it sense to me why you'd need to emphasize the task as opposed to the problem you'd be trying to solve. In rare cases I also adapted it to the SPARAR method, since the result made the problem smaller but didn't fully solve it yet.
I prefer to structure things on the fly though without a pre-defined framework.
