The idea being something like "charge at X € owed but let it go up to N*X € if a payment fails before suspending service" where the N scales with something like the number of paid invoices or even total past spend.,
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.
If I burn 1 € per day and my max owed based on whatever risk assessment is 20 €, I can set my payment treshold to 15 €, meaning if a payment fails, I have 5 days to fix it and settle the debt before you suspend my access. If the trigger amount is the same as the max owed, I have zero time (well, presumably there is already some wiggle room for the time it takes to process the transaction).