On Friday I did ISS injections at 3 different DARM offsets.  The change in the DARM noise for different DARM offsets can't be explained by these injections. 

The first attached plot shows the coupling from RIN on the ISS second loop (input beam) to mA on the DCPDs for the three different DARM offsets. At high frequencies the transfer functions from RIN to mA would be the same for different DARM offsets if the intensity noise was coupling through contrast defect light.  

The second attached plot shows intensity noise projections for all three DARM offsets.  I didn't correct the optical gain in the calibration for the 7.2 and 37.2 mA plots, so the calibration is off.  In any case, these projections are at least a factor of 10 below DARM.  This doesn't rule out intensity noise on the sidebands.  

For those who are interested the times of these injections are:

UTC times, December 8th 2018

20mA Injection:  7:55:12 quiet time: 7:49:44 

7.2 mA Injection: 7:59:26 UTC quiet time: 8:00:36

37.2 mA Injecton: 8:02:54 UTC quiet time: 8:04:25