WooCommerce Custom Plugin Development for Updating Subscription Product Orders

We need a solution that works with Multi-sites and is compatible with WooCommerce so Customers can place a product order and then later go back and update both the QTY and Frequency. So far we have used a "variable subscription type" to set Frequency and QTY as the drop-down choices. However, in order to accomplish this we needed to create four pages for one product which is not ideal. Unfortunately this method will not charge the credit card by default if the customer has placed the subscription and then changes the frequency. However, we know WooCommerce provides what is a called "Prorate Recurring Payments" options. You can read more here: [login to view URL] Currently Customers cannot update the order within the admin login area without having to go to the website as this is WooCommerce subscription functionality. You can read more about the customer options here: [login to view URL] We really would like to create a way for them to update their orders that makes it easy to understand and process. We also need an email triggered when customers switch the subscription frequency and/or QTY. We have currently used the "WooCommerce Subscribe All the Things" plugin: [login to view URL] to allow the one time and recurring options on one product. Unfortunately, this developer has not added a switching subscription feature. We have contacted the plugin developer and they responded with the following: "switching is not supported yet. It is on the Roadmap for WCS Features Parity Milestone 3 and 4 so I'm sorry to say it is still quite a long way off from being developed.": [login to view URL] We need your help to create a custom solution that will work with Multi-sites that will allow products to be updated in the admin area of the Customer's dashboard or at least a user experience that makes this process easy to understand, please help!!