Hello,

Firstly, regarding using the Page Builder plugin. You need to use only one on your Site to avoid conflict, either Elementor or WPBakery. As of now you have used Elementor, so you can get along with that.

Regarding the Template Library, it is available to use in both Elementor and WPBakery. Here is the GIF showing the working under Elementor editor:

https://xtemos.com/wp-content/uploads/screenshots/woodmart/template_lib_elementor.gif

Let us know if you need any further assistance in this regard !

Best Regards