I came really late to the spaniel tests, so from what I know the water blind has always been in place. A friend and Myself have only ran 2, both with HRCH MH Labradors. All I know is from us going to the first one, we learned how to be more quiet-sparing with our whistles, to give the dog more free range-trust on quartering and perhaps learned how to dance a bit (albeit not as gracefully as some Master spaniel handlers) on the strange thing which is a Hunt'emup blind. From the 1st to the 2nd test watching Labradors run, several spaniel people went home and bought a book on how to teach their dogs to handle-cast retriever style, which was evident in their Hunt'emups and water blinds. They needed it, water blind was an angle entry, angle across a pond, up on to land and dig it out, but don't go completely though a briar tunnel, a tad bit tricksy. Overall the information transfer has been good for all parties.
Also because we have transcended venues, we've had some spaniel people show up for our HRC upland test. They are just pretty to watch flush, and their handlers have so much trust in their dogs, make it look effortless. It was fun watching them try to get their dogs to heel, on the brace walk-up-honor, but by the second test they had it down. Good dog work is nice to watch-judge, regardless of breed.