Cool
I just added the BuiltIn file to the list of pages that MUST be loaded when exporting with the new submenu. So if PyPRP doesn't find it, it should automatically create it.
If the BuiltIn file exists, it should just overwrite it with a new one... but the contents of this file should always be the same anyway.
So theoretically, you can do a "normal" page export just after that, and the BuiltIn will not be modified but Plasma will load the Age fine.