To get more range out of MCL PZTs, I swapped the position of fixed and PZT mirrors. See D1400241.
| Mirror | before | now | |
| WFSA | ALS-M16 | fixed | PZT |
| ALS-M17 | PZT | fixed | |
| WFSB | ALS-M18 | fixed | PZT |
| ALS-M19 | PZT | fixed |
This should have increased the centering range of WFSA by a factor of 3.7, and WFSB by a factor of 9.4. Even though WFSB centering is heavily coupled to WFSA, there seems to be no problem.