Modern Tribe's The Event Calendar plugin edit event screen improvement.

Main.php

<?php
/**
 * Modern Tribe's The Event Calendar plugin would be much faster in the editing interface 
 * if it removed the upfront loading of organizers and venues from the select dropdown and 
 * relied on AJAX loading after initial page load. Additional improvement would be to drop 
 * the `get_the_title` method when displaying the venue and organizer titles in the list. 
 * This was tested on a production site with ~4500+ events. Average of 10 attempts time to 
 * load edit screen prior to modification 47.2 seconds with memory load 290.63mb and 
 * 18,968 queries. In contrast after modification 16.88 seconds with memory load 217.89mb 
 * and 155 queries.
 * 
 * The server environment is running middle package on WP Engine. The memory for the site
 * is bumped to 512mb. Caching is enabled for assets and objects. CDN is enabled.
 * 
 * Additional points of interest during the screen load is the following calls that occur
 * - After cleanup, occasionally `getEventMeta` and `isVenue` is called almost 6000 times each
 * - The Events Calendar Pro plugin is active an running. 
 * - The events tested are not recurring, they are a mix of all day and date with time based. 
 * - Some events have no organizer, some have one, some have several organizers selected.
 */

// file: the-events-calendar/src/Tribe/Main.php

// line: 1548 replace `$venue_title    = wp_kses( get_the_title( $my_venue->ID ), array() );`
$venue_title    = wp_kses( $my_venue->post_title, array() );

// line: 1596 replace `$venue_title = wp_kses( get_the_title( $venue->ID ), array() );`
$venue_title = wp_kses( $venue->post_title, array() );

// line: 1638 replace `$organizer_title    = wp_kses( get_the_title( $my_organizer->ID ), array() );`
$organizer_title    = wp_kses( $my_organizer->post_title, array() );

// line: 1685 replace `$organizer_title = wp_kses( get_the_title( $organizer->ID ), array() );`
$organizer_title = wp_kses( $organizer->post_title, array() );


/**
 * Follow up testing reveals some potential areas of improvement. First, the use of 
 * transients for storing lookup queries for venue and organizer could be beneficial 
 * to caching for large event sites.
 */
 
 /**
  * 2015-11-21 update:
  * after discussing with Tribe Support through a pull request I made several adjustments by removing the
  * wp_kses method and passing through the object to get_the_title in order to continue to leverage the 
  * `the_title` filter. Passing the object through reduces all the lookup calls even in a non-cached environment.
  * Removal of the kses methods does not resolve the issue of potential tags in the title but ideally that
  * would be handled on save vs display of the content. Thus if this case justifies the large majority case
  * it would make sense to continue down this path; however, in the case of a large set of venues/organizers
  * it might be better suited to allow performance tuning without modifying the plugin code via a filter. As 
  * identified earlier an AJAX call for this data would be most optimal to shove the processing to later 
  * stage while the admin page renders.
  * see the pull request: https://github.com/moderntribe/the-events-calendar/pull/422
  * wp_kses performanace article: https://www.tollmanz.com/wp-kses-performance/
  */
  
// file: the-events-calendar/src/Tribe/Main.php

// line: 1548 replace `$venue_title    = wp_kses( get_the_title( $my_venue->ID ), array() );`
$venue_title    = get_the_title( $my_venue );

// line: 1596 replace `$venue_title = wp_kses( get_the_title( $venue->ID ), array() );`
$venue_title = get_the_title( $venue );

// line: 1638 replace `$organizer_title    = wp_kses( get_the_title( $my_organizer->ID ), array() );`
$organizer_title    = get_the_title( $my_organizer->post_title );

// line: 1685 replace `$organizer_title = wp_kses( get_the_title( $organizer->ID ), array() );`
$organizer_title = get_the_title( $organizer->post_title );