The primary objective of the max-owed limit is to cap per-customer risk.

If you are suggesting that the max-owed limit is actually N×X, then that would multiply worst-case exposure by N, which is undesirable.

If you are suggesting that we charge the customer when they owe X while their max-owed limit is N×X, this would be worse for the customer, since they would pay `N × (X × variable_rate_fee + fixed_rate_fee)` instead of `N×X×variable_rate_fee + fixed_rate_fee` in payment processing fees.