Issues with the new export with live connection

I've been in contact with microsoft support.  Here is what they told me:

1.  The reason some visuals cannot be exported with the new option is that the visual includes a meaure that exists only in the dashboard instead of the datasource.  So if the export succeeded it woudn't work because that measure wouldn't be available in the live connection to the datasource.  If you plan on using this option make sure that all your measures are in the datasource instead of the dashboard.

2.  If I turn off building on the datasource in the service for that datasource (commonly used in analyze in excel), this new option will not appear for export since the user will not be able to connect to the datasource later.  This can be done individually for each datasource instead of a global tenant setting, but it will affect every dashboard that uses that datasource.

Since we have over 50 dashboards that use this datasource and also have users that connect to the datasource through excel, we are stuck with a big job of migration of measures to the datasource.  Any future dashboards with new measures will be added to the datasource so the export will work on those dashboards.  

I've submitted a request to PBI that an control be added to the report settings to allow the developer to select the export options much like the existing export level of detail options.  This will allow me to control this on a dashboard by dashboard basis.