I am developing a few themes and I am working from the elemental theme along with the full install with the fake site data.

In my theme default.php I am attempting to set the custom template of the page_list block type. i am using $a->setCustomTemplate('page_list', 'showcase.php'); The custom template does not apply to all instances of the block since during install the Thumbnail Grid template was applied to one of them. I am trying to avoid customizing the starting point for installation but will go that route if I have too. Does anyone know of a way to remove a custom template from a block during theme activation?