Today I ran Laddie on a wide open water blind and used two WSCs to make minor adjustments in his direction. Not a peep.
Then I ran him four times to the same target as yesterday, from the same two SLs. The only difference from yesterday was that today I used two white bumpers, which, predictably, he picked up first, and two orange bumpers.
The two times I ran him down the middle (the first and third retrieves), he lined it with no vocalization.
The two times I ran him in a line across a point (the second and fourth retrieves), he veered wide and I used a WSC to correct his line. He vocalized a little when cast, but took the casts without difficulty.
Today's work suggests to me, not that Laddie considers a WSC aversive, but that he considers crossing a point, or being directed to cross a point, aversive.
In any case, the vocalizations were minor, little whines rather than yelps. Hopefully that represents a diminished level of anxiety compared to earlier, more emphatic vocalizations, and a trend in the right direction, though a backsliding from yesterday.