Early Elimination in STV

Hi All,
I was wondering if anyone has written or thought about early elimination of candidates for the single transferable vote method.
I am aware STV is not precinct summable, nor can it be made precinct summable, because the outcome relies on the flows of ballots. However, I can imagine situations in which, even with only some ballots received, it's mathematically impossible for certain candidates to reach quota, and so we might wish to eliminated them early.
Unfortunately, depending on the counting method, even the order in which candidates are eliminated can affect the outcome of STV. So I suppose I'm actually looking for an answer to the question: is it possible to tell when a candidate can't win and can't change the count by being eliminated later, and if so, how.
Also, a related second question: I believe I have heard that the Meek counting rule makes elimination ordering not matter, but I can't find a source. Is this true, and if so, could someone point me at a good proof as to why this is so.
Thanks!