Last night before dinner, I copied over the ASC yaw servo filters to the ASC pitch filter bank.  Using ASC gain of +0.001, I was getting the ~250Hz oscillations that Rana and I had seen with yaw. 

Rana pointed out to me that my measured TF of the yaw loop doesn't look right up in the several hundred Hz region:

As you can see on the right side, which is all of the PRCL ASC yaw filter banks, multiplied by a simulated pendulum filter, the magnitude should just keep decreasing.  However, on the measured plot on the left, you can see that I have a little gain hump.  I'm not sure what this is from yet.