Plugin to turn off ContentBlocks by default

ContentBlocksDisabler.php

<?php
$eventName = $modx->event->name;
switch($eventName) {
    case 'OnDocFormRender':
    if ($mode == modSystemEvent::MODE_NEW) {
		$resource->setProperty('_isContentBlocks', false, 'contentblocks');
		}
    break; 
}