It takes a long time to damp 1.69Hz resonance in L DoF, I modified the NBDAMP filter of ETMX L5.
Origina filter was moved to FM2 (BP1.69_old) as shown in fig1.
New filter was implemented at FM1 (BP1.69) as shown in fig2, which BP frequency was shifted 0.04Hz.

After that, OLTF (fig3) seems to be healthy and damping performance was improved.