Summary--No answers yet but, Guardian still kicks RZ when Z ISO loop is started, command scripts don't; Guardian ST2 gain/whitening scheme still not right(believe we have corrected this now;) Isolation Loop Spectra amplified with MICH engaged.

1) See first attachment of 8 minutes of second trend.    T=1 is when the guardian turns on the Z Isolation loop as evidenced by the start of non-zero _Z_OUT16.  Notice above this channel, the _RZ_OUT16 is not on.  Notice though on the upper left plot how the RZ_INMON is influenced by the Z loop turn on at T=1.  About 30 seconds after T=1, the RZ loop turns on with a large spike.    At T=2, the Z loop is started with the command script and while the INMONs before the start times are different, the Z turn on does not do near the abuse to RZ as does the Guardian.  See the attachment of aLOG 17402 17042 for several more comparisons where the turn on is not possibly contaminated by watchdog trips and MICH influence.

Still, my conclusion, Guardian does something abusive when clearly it isn't necessary.

2) I need to have more time to understand exactly what guardian is doing during the steps but when Mich is locked and Guardian moves the ISI toward HIGH_ISOLATED, the gain/whitening of the Stage2 GS13 are switched to an analog whitened high gain state and trips immediately.  Again, I need to study this exactly as it isn't verbose in the Guardian Graph but this is my observation recollection.  With the MICH locked and the Stage2 tripped (which it did many times,) the ISI could not be untripped as the MICH was pushing the ST2 too much.  Maybe it would do it in low gain but I'm not sure I even tried that with Guardian doing its own thing.  I finally did get the guardian to leave the GS13 gains alone, obvious now to me, by using the command scripts where I could leave the GS13 in analog whitened low gain.

Conculsion: More test time needed but for now it seems the GS13 must be kept in whitened low gain when MICH comes on.  ADD ON--We found a spot in the Guardian and corrected this-see aLOG 17092.

3) By using the command scripts, I was able to turn on the Z and RZ ISO loops with Boost of ST2.  I then turned on the Y dof without boost and it managed to stay Isolated long enough to get reasonable looking spectra.

See second attachment: The lighter colored thicker reference traces were collected yesterday morning when I engaged all 4 loops without the MICH locked.  I can't recall now if I did this with the guardian or not.  This morning, finally with MICH locked, I got the loops on while running a 3 average exponential ASD.  The thin dark current traces are the Z RZ and Y Isolation OUTs.  I managed to pause the measurement before the trip contaminated these spectra.  Maybe the traces were settling down still at the time this spectra was frozen but, the Z RZ & Y loops were on for 180 135 & 45 seconds respectively before the measurement stopped.  Still, clearly, there is much elevation in the drive spectra from several 100hz down to 1 to 20 hz depeneding on the DOF.  Around 70-80hz, the increase is 2+ orders of magnitude.

Further conclusions w/JeffK--We will try to do similar with the Actuator Outputs (no  DQ channels.)  Otherwise, with this isolation output elevation and the shapes of the Actuator output filters, it isn't surprising that we could be near DAC saturation.