I attach a video of CC2 loop correction signal when squeezing is reflected by Input mirror.
It seems that the high frequency oscillation (from suspension pitch, due to beam miscentering on suspendend optic?) are not large enough to saturate the actuator, but probably 1 Hz pendulum motion does.
Would an increase of a factor 3 in piezo correction that we could gain by exploiting the whole piezo dynamic be enough to avoid CC2 unlock?
Why the correction saturates when it becomes negative and not when it becomes positive?