I posted on comments at your theme before I saw the support forum. Sorry.

When I set the featured image, the home page is loading the largest version of that image for every post preview so it is very slow. Is there something I can plug into the functions.php file to make it select a small thumbnail of the featured image so that the page loads more quickly?

I tried just plugging this in at the end of functions.php but it didn’t do anything.

add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 1024, 1024 );