Hi OK465,
Thanks for your interesting observations in what I assume was a simulator exercise. When I wrote about the phugoid I had no idea of the amplitude of the oscillations, and I understand they were so small that most pilots would not recognize it as a phugoid.
Just to complete my picture, since the amplitude may be expected to be a function of the magnitude of the 'disturbance' that initiated it, do you recall the gradient or rate of climb achieved in the stabilized climb?