Garvity forms filter gform_post_data

<?php
//This filter is executed right before the post is created, allowing post data to be manipulated before the post is created
add_filter("gform_post_data", "set_post_terms", 10, 3);
//post_data is the wordpress array used to create a post, form is the gravity form in the backend, entry is the info submitted by the form to the entries table
function set_post_terms($post_data, $form, $entry){

    //only do this when the form id is 2
    if($form["id"] != 3){
        return $post_data;
    }
    else
    {

        //push the new taxonomy college into the existing post_meta tax_input key
        $post_data["post_type"] = 'apprentice';
        $post_data["tax_input"][] = 'college';
        $post_data["tax_input"][] = 'type';

        //get values from submitted form (stored in entries)

        //interested because
        $interestBecause = $entry["36"];
        if($interestBecause == 'I am / would like to be an Apprentice') $post_data["tax_input"]['type'][] = 'apprentice';
        if($interestBecause == 'I am an Employer') $post_data["tax_input"]['type'][] = 'employer';

        //plumpton courses
        $plumpton = array(
            $agriculture = $entry["13.1"],
            $landBasedServiceEngineering  = $entry["13.2"],
            $engineering = $entry["13.3"],
            $horticulture = $entry["13.4"],
            $floristry = $entry["13.5"],
            $treesTimber = $entry["13.6"],
            $environmentalConservation = $entry["13.7"],
            $veterinaryNursing = $entry["13.8"],
            $viticulture = $entry["13.9"],
            $animalCare = $entry["13.11"],
            $horseCare  = $entry["13.12"],
            $foodManufacture = $entry["13.13"],
        );

        //sussex downs courses
        $sussexDowns = array(
            $accountancy = $entry["24.1"],
            $businessAdministration = $entry["24.2"],
            $customerService = $entry["24.3"],
            $enterprise = $entry["24.4"],
            $management = $entry["24.5"],
            $teamLeading = $entry["24.6"],
            $sales = $entry["24.7"],

            $retail = $entry["25.1"],
            $warehouseStorage = $entry["25.2"],

            $brickwork = $entry["26.1"],
            $CarpentryJoinery = $entry["26.2"],
            $maintenanceOperations = $entry["26.3"],
            $paintingDecoration = $entry["26.4"],
            $plumbing = $entry["26.5"],

            $cleaningSupportServices = $entry["27.1"],
            $foodBeverageService = $entry["27.2"],
            $foodService = $entry["27.3"],
            $beverageService = $entry["27.4"],
            $frontHouseReception = $entry["27.5"],
            $hairdressing = $entry["27.6"],
            $hospitalityServices = $entry["27.7"],
            $hospitalitySupervisionLeadership = $entry["27.8"],
            $housekeeping = $entry["27.9"],
            $kitchenServices = $entry["27.11"],
            $professionalCookery = $entry["27.12"],

            $culturalVenueOperations = $entry["28.1"],
            $liveEventsPromotion = $entry["28.2"],

            $childcare = $entry["29.1"],
            $clinicalHealthCareSupport = $entry["29.2"],
            $healthSocialCare = $entry["29.3"],
            $supportingTeachingLearning = $entry["29.4"],

            $maintenanceRepair = $entry["30.1"],
            $bodyPaintOperations = $entry["30.2"],
        );

        //Check if the form had both plumpton and sussexdowns courses checked
        if( count(array_keys($plumpton, false)) !== count($plumpton) && count(array_keys($sussexDowns, false)) !== count($sussexDowns)  ){

            $postCopy = array(
              'comment_status' => $post_data['comment_status'], // 'closed' means no comments.
              'post_author'    => $post_data['post_author'], //The user ID number of the author.
              'post_content'   => $post_data["post_content"], //The full text of the post.
              'post_date_gmt'  => $post_data['post_date_gmt'], //The time post was made, in GMT.
              'post_name'      => $post_data['post_name'], // The name (slug) for your post
              'post_status'    => $post_data['post_status'], //Set the status of the new post.
              'post_title'     => $post_data['post_title'], //The title of your post.
              'post_type'      => 'apprentice', //You may want to insert a regular post, page, link, a menu item or some custom post type
              'tax_input'      => $post_data['tax_input']
            );

            $postCopy["tax_input"]['college'][] = 'sussex-downs';

            wp_insert_post( $postCopy, $wp_error );

            $post_data["tax_input"]['college'][] = 'plumpton';
        }

        //count the number of array keys that are false, if this count isn't equal to the number of array values at least one has been ticked
        //plumpton
        elseif( count(array_keys($plumpton, false)) !== count($plumpton) && count(array_keys($sussexDowns, false)) == count($sussexDowns) ){
            $post_data["tax_input"]['college'][] = 'plumpton';
        }

        //count the number of array keys that are false, if this count isn't equal to the number of array values at least one has been ticked
        //sussex downs
        elseif( count(array_keys($sussexDowns, false)) !== count($sussexDowns) && count(array_keys($plumpton, false)) == count($plumpton) ){
            $post_data["tax_input"]['college'][] = 'sussex-downs';
        }

        return $post_data; //return the changed data to use when the post is created
    }
}