How can we improve WHMCS?

When a Stripe SEPA payment is created through WHMCS, it will create a customer in Stripe. There, in our case, it will always set the customer's language to English. This will cause Stripe to send them an English SEPA payment notification via E-Mail as well.
As we have customers from different countries, this could be confusing to non-English customers.
It would be great if WHMCS could also submit the customer's language from WHMCS to Stripe. Currently we are updating the customers manually whenever a customer submits his first SEPA payment. It would be great if this manual task is not necessary anymore in the future.