I understand your frustration and the lack of transparency and inability to meet promised deadlines has irritated me in the past as well.
If I had to bet, I don't think we're ever going to see a BFS. The reasons for this are many, but most importantly, it takes the ability to scrutinize the deal between teck and cuu off the table, which makes things a lot cleaner. I think it's in teck's best interest to settle before the bfs is released and that's exactly what they'll do. I'd bet that the BFS is already finished and teck is reviewing it and negotiating a price. If I'm proven wrong, I'll be disappointed, but my gut tells me a deal will be made within the next 4-6 weeks and I sure as hell won't be sitting on the sidelines watching the parade go by.