I was honestly hoping to learn a new trick from you! I sail a Hobie Wave, before that a Hobie 16. So I know all too well the hazards of going back to lock the rudders down.
In reality, I (and probably most of us who have done this for any amount of time) do our best to balance inching the rudders down as the water gets deeper, but not locking them down until we believe that we're in deep water.
Maybe it's for the best, though. Nothing destroys a transom faster than backing down a wave, with rudders locked down, and hitting the seabed.
Of course, most times, we aren't racing as soon as we launch. The Worrell, Tybee, Florida 300 and Great Texas guys may have a different approach?