Here is the Sensing Matrix movie (sorry for the iffy quality - my movies usually come out better than this):

This is the sensing matrix for the sideband locked on PRMI, bringing the Xarm into resonance from anti-resonance, in 20 equally-spaced steps.  You can see the microscopic ETMX offset (units of meters) in the title of the figures.

I was surprised to see some of the 'jumps' in the sensing matrix that happen near the end, when the arm is almost in resonance.  I'm in the process of making movies of the error signals as the Xarm is brought into resonance.  I'll have to post those in the morning, since they're taking a long time to produce and save, however when I looked at a few, there is some weird stuff going on as we get close to resonance, even with the 3f signals. 

The modeling phone call is in the morning, but if anyone who is not regularly on the call has thoughts, I'm all ears.