After Sheila and Alexa realigned the arm by hand (arm transmission ALS-C_TRX_LF_OUT about 700cts), we removed the dark offset of WFS demode output, confirned that RFAM is negligible by misaligning the ITM but aligning the ETM, then centered and engaged WFS, but it did not converge.

We had to refine alignment further (760 cts transmission), disable the PDH off-loading to the ETM (the length to angle coupling is large even at low DC),  recenter the WFS, engaged WFS, wait for a while, hold the WFS output, recenter the WFS, and it worked with all except one DOF (DOF2 PIT, which is the soft mode PIT).

For now the hard mode sensor for PIT and YAW are WFSB and WFSA, respectively, while the soft mode sensors for PIT and YAW are WFSB and WFSA. The WFSA and WFSB seem to be highly degenerate for PIT, and that's probably why it's very difficult to make both DOF1 and DOF2 PIT at the same time.

Anyway, after three DOFs are engaged the transmission went up to 860+ cts maximum. We left the arm with WFS on.

Note that it's still with very small bandwidth (basically just DC).