Attached are plots of oplev signals of ETMY and ITMY, as well as the arm cavity reflected power (ALS-Y_REFL_B_LF_OUT).
Plot 1 shows the signals in lock.
Plot 2 is a time series in lock.
Plot 3 shows the same signals as plot 1, but out of lock.
Note that neither channel is properly calibrated yet. (TBD)

Conclusion:
- The limiting peaks are ~0.44Hz and ~0.55Hz.
- Both ETMY and ITMY show the motion.
- Our slow feed-back of the length signal to ETMY M0 makes them worse for ETMY in-lock.