I did the following:

1. Checked the ETMY OSEM sensing matrix and OSEM actuation matrix - more on this later, but everything seems much more reasonable than it was prior to this vent.
2. Checked that the IMC could be locked with the low-power beam
3. Aligned the Y-arm cavity using the green beam. Then tweaked the TT1/TT2 alignment until I saw IR flashes in TRY.
4. Repeated #2 for the X arm, using the BS to control the beam pointing.
5. Confirmed that the AS beam makes it out of the vacuum. It is only ~30uW in a large (~1cm dia) beam, so not the clearest spot on an IR card, but looks pretty clean, no evidence of clipping. I removed an ND filter on the AS port camera in order to better see the beam on the CRT monitor, this should be re-installed prior to ramping the input power to the IMC again.
6. With the PRM aligned, I confirmed that I could see resonant flashes in the POP QPD.
7. With the SRM aligned, I confirmed that I could see SRC cavity flashes on the AS camera.

I think this completes the pre-pumpdown alignment checks we usually do. The detailed plan for tomorrow is here: please have a look and lmk if I missed something.