Strange that the partner needs to be pay, with most payment gateways is the other way around. The developer works to bring more customers and a higher sales volume and the payment gateway in return does revenue sharing.
(I work at Stripe.) This program is designed for platforms (specifically platforms that use Stripe Connect with standard accounts) and extension partners. The new benefits for partners include best practices, resources to help them promote their integration, and new ways to reach customers. Happy to help clarify if there’s anything in particular!