Unset or validate a field in a Gravity form

<?php
# For Gravity Forms. Sometimes a form has a checkbox or radio button that is not always required - agree terms or confirm something.
# In this case it is a radio button to confirm that the person submitting the form is insured before they sign up for a subscription.
# Some supscriptions require that the user confirms insurance status, some do not.
# These functions remove the field if it is not needed, validate it if it is.


# ------------------------------------------------------------
#  Unset insurance field if it is not required
# ------------------------------------------------------------

add_filter("gform_pre_render_3", "sd_unset_insured");

function sd_unset_insured($form){
    // the label of the insurance field
    $insuredfield = array('Insured');
    global $post;
    // get post meta to check if insurance is required
    $needsinsurance = get_post_meta($post->ID,'_sd_product_insurance',true);
    // If value is 0, not required so unset
    if ($needsinsurance==0) {
        foreach($form['fields'] as $key=>$field) {
            if(in_array($field['label'], $insuredfield)) {
                unset($form['fields'][$key]);
            }
        }
    }
    return $form;
}

# ------------------------------------------------------------
# Validate insurance field if it is required
# ------------------------------------------------------------


add_filter('gform_validation_3', 'sd_require_insured');
function sd_require_insured ($validation_result){
    // the relevant field by form id and field id
    $insured = array("3:9");
    $form = $validation_result["form"];
    global $post;
    // get post meta to check if insurance is required
    $needsinsurance = get_post_meta($post->ID,'_sd_product_insurance',true);
    // If value is 1, required so validate
    if($needsinsurance==1) {
    foreach($form['fields'] as &$field){
        // find out if the field exists
        if(in_array($form["id"] . ":" . $field['id'], $insured)){
            $insuredinput= RGForms::post("input_{$field["id"] }");

             // if no confirmation is indicated, return an error
            if(!isset ($insuredinput) || $insuredinput!=1) {
                $field['failed_validation'] = true;
                $field['validation_message'] = 'You must confirm that you are insured';
                $validation_result['is_valid'] = false;
                $validation_result['form'] = $form;
            }

        }
    }
        }
    return $validation_result;
}