I am (was) able to get the mode cleaner mostly locked, but because WFS2 wasn't centered, the MC would drift, then lose lock. I recentered both the WFS (after unlocking the MC and the MZ), and am now about to commence relocking both of those.
Note to self: WFS get centered based on the direct reflection from MC1. Once the MC is close enough, the WFS are enabled, and they twiddle all 3 MC mirrors to minimize their error signal. Moral of the story: make sure the WFS are centered.