I don't really see the train defuse being an issue. It doesn't give anyone an advantage. I guess you could say the ct is more hidden, but really, is he any more protected? Not enough to matter imo. And I've never heard anyone ever complain about someone defusing from that spot. I never even heard of it as an exploit til this thread. The inferno thing I can see, even though I never heard of that one either. But in that case, it does interfere with defusing(I guess, never seen it).