Last week, we ran a transfer function of MC2 Top BOSEMs with some of it's cables intentionally grounded (shorted them with a small section of wire to metal in the chamber).  The attached plot shows the grounded longitudinal TF trace (blue) with the non-grounded trace (red), as well as the "nominal" trace taken during Phase 2b (black).  We do not see much difference in the noise between the grounded and non-grounded traces.  Note, the red and blue were taken with the purge on and soft covers off so the peaks are flattened a bit due to air damping.