My opinion is to have both plateaus and the swale maintain as a greens surface and not fairway length. Having played examples of both options, I feel that it is too vague when the first plateau is fairway length. For example, could any hole with a low area in front now say it has a "biarritz-style" green complex?
Also, to say it offers more "options" to play from the front plateau when it is fairway length, to me that just makes it less distinct. You can pitch, chip, putt, bump-and-run, etc. on any green that doesn't have a forced carry, why do we need it here?
Anecdotally, I played a nothing-special-about-it golf course a few years ago, and one of the par 4's had a large swale in front of the putting surface. My cousin skulled his approach and it ran through the swale and onto the green. It functioned the same way, but I wouldn't want to call that a Biarritz hole.
I know that was rambling and neurotic, but put my vote for maintaining it all as putting surface, even if it can be proven that it isn't the "correct" way to build it.