Any plugin that implements post types and taxonomies has to deal with the theme and it needs templates to display new content that is able to include all the extra stuff that the plugin might need. And, the GD Knowledge Base is adding 5 new post types and 4 new taxonomies, and it can display the content in the ways that normal WordPress theme templates just can’t do out of the box. And, you can’t ship templates for all kinds of themes in the plugin, it is just not a viable approach.
Since version 2.0, GD Knowledge Base Pro works with any theme. It uses theme compatibility mode based on the code developed for bbPress and BuddyPress (by John James Jacoby). It works by using standard page.php template (or index.php if page.php is missing) and buffering the real content to place into the page. Because of this, every theme will work with this plugin, and it will use default styling, that should match most themes to a point.
The plugin includes default styling and basic grid stylesheet to make the knowledge base responsive. The default styling is tested with various themes to make sure it looks consistent across different themes. Still, you can adjust styling through your theme if you want to make changes. It is a much smaller change to the theme than providing the templates for the plugin.
And theme customizations
And yes, if you want, you can make the specific templates for your theme, and override what the plugin is doing every step of the way. And, the plugin license includes additional downloads with example child themes on how to do all that, that can be used as starting point.
Basically, you can use this plugin in two ways: create needed templates to make your theme fully compatible, or don’t create templates so that plugin can run in theme compatibility mode. The choice is yours.