And…
It’s here already! Requests can be done via the NumFOCUS rocket page. That should then send the admins a message for approval, and, once approved, the payment will be processed.
@astrojuanlu - I’ll send you privately the amount you need to claim for (unfortunately, we can’t pay extra tax for late payment )
The form seems to be geared towards asking for specific refunds. Given that this might be a special case, I used it anyway, introducing the Open Collective bank details, and will continue the discussion with NumFOCUS.