Comparing arrays with meta_query in pre_get_posts

The ACF Documentation recommends checking the values individually rather than simultaneously using an array.

The following code is from the ACF Documentation for the Checkbox field type:

http://www.advancedcustomfields.com/resources/field-types/checkbox/

/*
*  Query posts for a checkbox value.
*  This method uses the meta_query LIKE to match the string "red" to the database value a:2:{i:0;s:3:"red";i:1;s:4:"blue";} (serialized array)
*  The above value suggests that the user selected "red" and "blue" from the checkbox choices
*/

$posts = get_posts(array(
    'meta_query' => array(
        array(
            'key' => 'field_name', // name of custom field
            'value' => '"red"', // matches exaclty "red", not just red. This prevents a match for "acquired"
            'compare' => 'LIKE'
        )
    )
));

Therefore the query in pre_get_posts should look like this:

$filter = array(
    array(
        'key' => 'delivery_method'
        'value' => '"Online"'
        'compare' => 'LIKE'
    ),
    array(
        'key' => 'delivery_method'
        'value' => '"Scheduled"'
        'compare' => 'LIKE'
    )
)

$query->set('meta_query',$filter);