The IMC stayed locked last night, but with a high REFL ~3.0. I found the WFS servo OFF; so went ahead and enabled it. (Did somebody disable it for reasons not elog'd?)
MC returned to a happy state. But the WFS offsets are quite large. So I tweaked the alignment and got MC REFL down to ~0.45 and MC TRANS SUM to ~16500 counts. MC WFS offsets also dropped significantly after this without any need to touch the alignment to the WFS PDs.