The following document outlines how to use the "Inherit VLDB" setting available in drilling to either inherit or not, VLDB properties from a template when drilling to it.
The property can be seen below and is called "Inherit VLDB".

The Inherit VLDB property has two options; true and false.
If it is set to true then VLDB properties that are not set to default at the source report level are inherited by the report being drilled to. This will override properties of the template being drilled to if they are not set to default. If properties are set to default at the source report and not default on the template then they will still be inherited from the template.
If the property is set to false, then VLDB properties not set to default on the template will override properties not set to default (or set to default) on the source report. However properties that are not set to default on the source report that are default on the template will still be inherited from the source report.