Someone who knows supplements would have to answer that, however they can identify metabolites and still bust you if they wanted to really dig deep enough to get you.
I'm thinking 4AD, but again someone who knows supplements would have to answer.
Yes the gear test is expensive, which is why its not likely, and they really dont expect you to be using steroids most of the time unless you really look like you are using, and even then I expect some kind of special permission needed to justify the cost and it still may be somewhat random (not testing for gear bi-weekly).
Good luck