How to Apply Panelizer on already created nodes of a particular node type? I've got a content type Article
with created nodes of that content type

Then I decided I want to use Panelizer, but i discovered I have to manually modify each node to apply panelizer

-I enabled the "Node template" display in the Pages admin (admin/structure/pages).
 - I have tried Display Suite, but I want to use Panelizer

Its like the node will have its own Panelizer isolated from global Panelizer settings.
The module's lead maintainer, merlinofchaos, responded to this on drupal.org; in short, it's only possible if using the IPE, there's an option to make the changes global i.e. affect the default configuration, otherwise the changes have to be made via the entity's Panelizer tab, e.g. admin/structure/types/page/panelizer.