RichM pointed me to look at the RZ drive as a way to confirm that the Z 45mHz blend is not coupling T240 RZ into the platform.

The attached 24 hour trend at ETMX suggests the nice reduction of inertial Z motion on Stage2 GS13s does not come at the expense of increase drive to the RZ of Stage1.  Our z-RZ subtraction is doing well.  The Blend switch points are shown too.