To check if the reason of OMC DC PD saturation is the suspension kick, I locked PRFPMI without engaging whitening filter for OMC DC PDs.
It degrades the ADC noise and noise floor got slightly worse, ADC range at high frequency increases by a factor of 10.
So, if the large suspension kick is the reason of the lockloss, it would help t keep the lock.
To keep this configuration, I modified the OMC_LSC guardian as shown in fig1.