Show specific posts with WP_Query using ACF Post object

now we are getting there.. you really need to try to explain, what your problem is, its not very clear in your question.

my assumption is, you tried this one, but it didn’t work out:

foreach( $post_objects as $post_object):
  get_template_part( 'includes/content', get_post_format( $post_object->ID ) );
endforeach;

and here is why: you call the template, but the global $post is still set to the previous post/page. you need to set the global $post variable as you do it later on in your code ($all_presentations->the_post();). it works differently, when you do it in a foreach and not with WP_Query(), but you can set the global $post variable when you hand and object of that post to setup_postdata. when you do that, you can call all the other functions, like the_title() or the_content() and wp will grab it from the object, that you provided.

here is how:

<?php
 /**
   * when you call the_title() here, it will return the title of the current post/page (global $post defined by main query)
   */
if( $post_objects ):
  foreach( $post_objects as $post): //!!the variable MUST be called $post
    setup_postdata($post); //set new $post_object
    /**
      * now we switched global $post, so the_title() will return other the contents of your $post_object
      */
    get_template_part( 'includes/content', get_post_format() );
  endforeach;
  wp_reset_postdata(); //reset global $post
endif;
?>

you need to call setup_postdata()on your obect, to use get_post_format(). see the docs for more info on setup_postdata.