Good to see the latest bruco result! There are several interesting features. Let's visit the link and check the features by oneself. In my impression, while we need ASC so that it would eventually help MICH noise reduction, it is important to do PEM injection study to IFI chamber legs to identify the main path(s) of the noise transfer, and damp the paths would be also effective. Some contributions from power-supply-like voltage fluctuations would be also interesting. And PSL room follows.
I am afraid the relative position of the IMMT1 Trans QPD against mirrors on the periscope in the PSL room moves because of water pressure inside the mountain. If so, some offset can change the optical path from the PSL room to IMMT1 and show some changes in resonances.