I drove a 222.3 Hz line in the 9 MHz RFAM stabilization error point (giving 3.4×10−4 RAN rms) and then watched the resulting lines in REFL LF and ASC NSUM as we powered up from 2 W to 25 W. [Note that the DC readback of the RFAM servo really does give us a RAN, not a RIN. This can be verified by noting that the dc value changes by a factor of 2 when the rf power is reduced by 6 dB.]
At 2 W, we have 0.013 W of 9 MHz power reflected from the PRM and 0.0007 W of 9 MHz power coming out of the AS port.
At 25 W, we have 0.11 W of 9 MHz power reflected from the PRM and 0.034 W of 9 MHz power coming out of the AS port.
The lock stretch happens around 2016-10-25 00:21:00 Z if anyone wants to look at it.
The values for the reflected PRM power still seem to imply that the 9 MHz sideband either is not strongly overcoupled to the PRC, or the modulation depth is smaller than the old PSL OSA measurement (0.22 rad). For 0.22 rad of modulation depth and strong overcoupling, we'd expect something like 0.045 W reflected off the PRM at 2 W of input power. Also, the amount of 9 MHz leaking out the AS port evidently does not scale linearly with the input power.