Woocommerce subscriptions: Assign different subscrption_id to each item in cart

Question

I am using Woocommerce with the Woocommerce Subscriptions plugin and I am trying to assign different subscription_id to each item in the cart. So far I have managed with the following functions to split the cart items when quantity > 1, as you can see from the images I attached but they go all under the same subscription id. Any suggestions would be appreciated.

function1:

function split_products( $cart_item_data, $product_id ){
  $unique_cart_item_key = uniqid();
  $cart_item_data['unique_key'] = $unique_cart_item_key;
  return $cart_item_data;
}    
add_filter( 'woocommerce_add_cart_item_data', 'split_products', 10, 2 );

function2:

 add_action( 'woocommerce_add_to_cart', 'split_products_to_separate_cart_items', 10, 6 );

function split_products_to_separate_cart_items( $cart_item_key, $product_id, $quantity, $variation_id, $variation, $cart_item_data ) {    
    if ( $quantity > 1 ) {
        WC()->cart->set_quantity( $cart_item_key, 1 );
        for ( $i = 1; $i <= $quantity -1; $i++ ) {
            $cart_item_data['unique_key'] = md5( microtime() . rand() . "Hi Mom!" );
            WC()->cart->add_to_cart( $product_id, 1, $variation_id, $variation, $cart_item_data );    
        }
    }    
}

With these two functions above I manage to separate the cart items as you can see from the image below:

separated cart items

But unfortunately they get interpreted as one subscription with common subscription id (2544) as you can see from the following image:

common subscription id

Answer 1

You need to also modify recurring cart key for each item by using the following filter

add_filter( 'woocommerce_subscriptions_recurring_cart_key' );

Which is found in Class class-wc-subscriptions-cart in line 1088