Pro Sites - Affiliates - no payout options per level?

I installed Pro Sites and the Affiliates plugin because it says they're integrated and I can pay affiliates a commission for referring new paying members. When I set it up and go under Pro Sites for the options, it has a spot to enter the payment amount for 1 month, 3 months or 12 months. But that's it. The logical thing would be to have different payment amounts for each level. If the customer is paying more every month, I'd like to pay the affiliate more. I can't believe there isn't an option for that. Am I missing it?