Customizing Jetpack Portfolio default, NOT shortcodes

Working on this site: http://johnoseadna.com/

Self-hosted WordPress install, most current WP version, theme is a child of Blask.

Right now I’ve got the non-shortcode JP Portfolio showing on the fixed front page, which gets the portfolio content and formatting via portfolio-page.php.

I’ve got secondary pages set up to sort-of filter my work into categories that correspond to Portfolio project types (Design and Illustration in this case) and I’ve used shortcodes to display the projects on those pages:

http://johnoseadna.com/design/ and http://johnoseadna.com/illustration/

What I’d like to do is create modified duplicates of portfolio-page.php named, say, portfolio-page-design.php and portfolio-page-illo.php, and tweak the code so that it only displays projects with the appropriate type. (I found a support thread on that somewhere but can’t seem to locate it again. It was somewhat helpful but didn’t actually provide a solution.)

The goal is to have a consistent look for all of the portfolio categories on the site, which is a pretty standard need for most artists and designers.

I found a thread asking about this a year ago which gives a GitHub link, but the GH link is for shortcodes, not the main portfolio itself. This isn’t helpful, really.

I know I can just give up on portfolio-page.php, but I much prefer the way it handles the display of projects. I just want some of the same controls as in a shortcode!

I’ve tried the changes below in a file named portfolio-page-design.php and it returns a “no results found, would you like to search?” message rather than any projects. (The rest of the file is identical to portfolio-page.php, and in the right place in my folder structure; it just doesn’t return results.)

<?php
				if ( get_query_var( 'paged' ) ) :
					$paged = get_query_var( 'paged' );
				elseif ( get_query_var( 'page' ) ) :
					$paged = get_query_var( 'page' );
				else :
					$paged = 1;
				endif;

				$posts_per_page = get_option( 'jetpack_portfolio_posts_per_page', '10' );
				$args = array(
					'post_type'      => 'jetpack-portfolio-design',
					'nopaging'		 => 'true',
					'posts_per_page' => $posts_per_page,
					'paged'          => $paged,
					'order'			 => 'rand',
				);
				$project_query = new WP_Query( $args );
				if ( post_type_exists( 'jetpack-portfolio' ) && $project_query -> have_posts() ) :
			?>