In case anybody has the same problem/question and you happen to come across this post: I contacted Woo support regarding the question and asked whether Woocommerce Order Status Control plugin would enable me to do what I described. After receiving a useless AI-genereted answer and asking for a human to answer me (and waiting for a day), I actually got a solution from the support:
  1. Install Code Snippets plugin if you haven't: https://wordpress.org/plugins/code-snippets/
  2. Copy/paste this code into the .PHP section:
add_filter( 'woocommerce_payment_complete_order_status', 'wc_set_addon_orders_to_processing', 10, 3 ); function wc_set_addon_orders_to_processing( $status, $order_id = 0, $order = false ) { if ( 'completed' !== $status ) { return $status; } if ( ! $order && ! $order_id ) { return $status; } $order = $order ? $order : wc_get_order( $order_id ); if ( $order ) { $items = $order->get_items(); foreach ( $items as $item ) { if ( ! empty( $item->get_meta( '_pao_ids' ) ) ) { $status = 'processing'; break; } } } return $status; }
Seems to be working for me!