Luthers100 Hi
I got your point but there must be misunderstanding here about T4 Page Builder.
Basically, you can edit pages , Joomla articles, custom HTML modules created with T4 Page Builder only. The default Joomla pages in JA Athena template are Joomla pages, you must edit via template or the menu items of these pages, they can't be edited via T4 Builder.
I hope it makes senses.