Hello Bo,
You are absolutely right: it is strange that this has not happened until now.
I am fairly certain that there will be many cases where the effect is subtle but beneficial.
The occasional dramatic effect is probably most noticed when a single standout flier either puts in a barn-burner (and depresses everyone else's normalized scores) or passes up the opportunity to fly the round.
I do remember overhearing a discussion between flyers at a local contest almost 20 years ago that if the sure winner would sit out the last round (having already mathematically won the meet ) that the two of them could then properly fight it out in the one remaining round. The one that earned the 1000 would would almost certainly win second place and the previous 5 rounds would have had diminished effect.
The mere fact that such a discussion took place underscored the weakness in the old single score normalization.
Regards,
Dean Pappas