I cannot stress enough how the last site I built using woocommerce will be the last time I use woocommerce. You’re better off creating a subdomain and linking to a proven solution like bigcartel or shopify that doesnt break with every update and has great support around paid services.
If you’re going to build and sell extensions have the proper support for them. Don’t tell your clients that you can’t help unless it is also built on a WooTheme. Talk about railroading a customer into just using your product.