We measured the OMC Stack TFs (Z -> Z/X/Y), for 3 times: morning time (before the installation of the extended breadboards ), before connection, and after connection.
By connecting the upper stages, the vertical TF changed from 3 to 2 modes, as expected.
(Some small structures are found between the 1st and the 2nd mode. Due to the things located on?)

I summarized the each peaks (Z -> Z) for before and after the connection.

At 82 Hz, the amplitude was changed from about -5dB to about -10dB.
At 92 Hz, the amplitude was changed from about -3dB to about -15dB.