This is the first time I've come back to this thread since I made my post earlier. I was absolutely convinced that I had said that we say "I'm at baggage reclaim". I was genuinely shocked to see that my post read "in baggage reclaim".
I would like to make it quite clear now that, in my opinion, in BrE, we say either "I'm at baggage reclaim" or "I'm in the baggage hall".