Also, this thread is a completely dead duck without this (thanks to kazakore from another thread ( Enabling The Formula Meta Device ) ):
<filterdevicechainclipboard doc_version="0">
<devicecontainerslot type="SequencerTrackDeviceChain">
<devices>
<sequencertrackdevice type="SequencerTrackDevice">
<isactive>true</isactive>
<isselected>false</isselected>
<selectedpresetname>Init</selectedpresetname>
<selectedpresetismodified>false</selectedpresetismodified>
<ismaximized>true</ismaximized>
<customdevicename>Mixer</customdevicename>
<panning>
<value>0.5</value>
<visualization>Device only</visualization>
</panning>
<volume>
<value>1.0</value>
<visualization>Device only</visualization>
</volume>
<surround>
<value>0.0</value>
<visualization>Device only</visualization>
</surround>
<postpanning>
<value>0.5</value>
<visualization>Device only</visualization>
</postpanning>
<postvolume>
<value>1.0</value>
<visualization>Device only</visualization>
</postvolume>
<smoothparameterchanges>true</smoothparameterchanges>
</sequencertrackdevice>
<formulametadevice type="FormulaMetaDevice">
<isactive>true</isactive>
<isselected>true</isselected>
<selectedpresetname>Init</selectedpresetname>
<selectedpresetismodified>true</selectedpresetismodified>
<ismaximized>true</ismaximized>
<formulaparagraphs>
<formulaparagraph></formulaparagraph>
</formulaparagraphs>
<functionsparagraphs>
<functionsparagraph></functionsparagraph>
</functionsparagraphs>
<inputnamea>A</inputnamea>
<inputnameb>B</inputnameb>
<inputnamec>C</inputnamec>
<editorvisible>true</editorvisible>
<panelvisible>1</panelvisible>
<inputa>
<value>0.0</value>
<visualization>Device only</visualization>
</inputa>
<inputb>
<value>0.0</value>
<visualization>Device only</visualization>
</inputb>
<inputc>
<value>0.0</value>
<visualization>Device only</visualization>
</inputc>
<desttrack>
<value>-1</value>
<visualization>Device only</visualization>
</desttrack>
<desteffect>
<value>-1</value>
<visualization>Device only</visualization>
</desteffect>
<destparameter>
<value>-1</value>
<visualization>Device only</visualization>
</destparameter>
</formulametadevice>
</devices>
</devicecontainerslot>
</filterdevicechainclipboard>