Create wp_cront events dynamically upon user submission

A simple and dynamic way to use WordPress cron would be to set up an action hook for your schedule then only add scheduled events as and when you need them. The events would call a generic function and pass in your specific custom post type details through $args –

add_action('my_schedule_event', 'generic_function');

function set_schedule($post_id) {
    $time = strtotime(date('Y-m-d H') . ':00:00');      
    $args = array('post_id' => $post_id);        
    wp_schedule_event( $time, 'hourly', 'my_schedule_event', $args);
}

function generic_function($post_id) {
    // do your thing
}

So in lmk_alter_method_name() you call set_schedule($post_id).

Hope that helps!