Fundraiser Proiect - Custom fields - Post Parts

Hello there,

I'm using Upfront/Posts/Custom Post then Post Type/Project to display my project window.
From there, I have the left menu with with the General Settings/Post Parts Settings where I can pick post parts to display (ex: Date posted, author, gravatar, comment count, featured images, title, content, read more, tags, categories and meta)

I added an mu-plugin with the following code you provided previously to display total number of backers

function num_of_backers( $atts ) {
$atts = shortcode_atts(
array(
'post_id' => '1,2',
),
$atts
);
$backer_total = wdf_total_backers(false, $atts['post_id']);

return 'Number of Backers: '.$backer_total.' supporters!';
}
add_shortcode( 'number_of_backers', 'num_of_backers' );

When my project window showed up, I have the following structure

Featured Image
Author
Title
Content
Read More...

I would like to be able to add in that same project panel a line after the Read More to display the number of backers by using the shortcode

Questions:
1) How can I display the number of backers after the READ MORE post part (by adding a break line) ?
or
2) Can I modify the READ MORE function and add that shortcode in the php script? Where would it be?
or
3) Can I add a totally new Post Part to my Post and add it after the READ MORE post part? (that would be the best). If possible, can you provide some guidance?

I took a look at your plugin custompress, is there a way to do #3 with it?