I measured IM-L transfer function this morning. At low frequencies the coherence looks better now than yesterday. This likely means that the low coherence was produced by the suspension still moving a lot because of us having worked with it shortly before the measurement.  The coherence is still low below 20 mHz, a feature that also  happens in other PR3 transfer functions. In SR3 IM TFs at those frequencies the coherence tends to be higher.