I sent you an email but I'm not sure if you received it or not. I ran into a bit of trouble using the CollapsingQParserPlugin with elevated documents. To explain it simply, I want to exclude grouped documents when one of the members of the group are contained in the elevated document set. I'm not sure this is possible currently because as you explain above elevated documents are added to the request context after the original query is constructed.
To try to better illustrate the problem. If I have 2 documents docid=1 and docid=2 and both have a groupid of 'a'. If a grouped query scores docid 2 first in the results but I have elevated docid 1 then both documents are shown in the results when I really only want the elevated document to be shown in the results.
Is this something that would be difficult to implement? Any help is appreciated.