I have locked PRX using the ALIGN_IFO guardian node, after a bit of alignment tweaking by hand.  In particular, ITMX is quite far from where it was.  PRX is not yet aligned well, since I got distracted trying to close the REFL DC centering loops (which are now closed). 

Next up:

• Rephase RF PDs, both LSC_REFL and REFL WFS. 
• Measure REFL DC centering loop OLGs, especially DC2 for REFL_B.
• Engage WFS loops, and hopefully be able to have them track the alignment change as ITMX is brought back closer to the alignment that has been in use for the last week or so.

I think there are some sign flip shenanigans going on, which I think that I have fixed and they make sense now. But, the DC2 centering loops are still unstable for their old nominal gains.  Right now the gains are lower by a factor of 4 - increasing them causes the loops to go unstable.

Recall that in alog 40853 JeffK flipped some signs so that the suspensions were matching the proper sign conventions.  TVo, Sheila, and others found that this meant they needed to flip the feedback signs in the AS DC centering loops, as noted in alog 41436.  In that alog, Sheila preemptively flipped the signs also in the REFL DC centering loops.  However, as Jeff noted in his alog, RM2 didn't need the sign flip that the other *Ms did.  So, just flipping the DC centering loop sign isn't quite the right thing.  In the end, I put the REFL DC centering loops back to their previously nominal negative signs, and then flipped the sign of the RM1 elements in the ASC pitch and yaw output matrices, leaving the RM2 elements alone.  I think this achieves the correct sign-flippage.  But, the DC2 loops are still unstable when I go to their full gains (-10 for pit and -12 for yaw).  So, for now they're set at -3 for both pitch and yaw.  Tomorrow I'll measure the loops and see what's going on.

Attached is the alignment slider screenshot of where I have things right now.