Product Add-Ons for WooCommerce

We need more extensive features that works with subscriptions.

We have a problem where we use woocommerce subscriptions to set payment terms of 3months, 6months, 9months, 12months etc etc

But we also offer product addons and want those to also honor the subscription cycle chosen by the customer. But at the moment, it charges the FULL price of the addon every month instead of allowing us one of three options:

1. Bill full price of addon monthly along with subscription cycle

2. Bill addon price with split payments according to subscription length

3. Bill once off separate from subscription length

The above options would make it much more flexible to use product addons with subscriptions.