Managing Waterfall/Claysearch: Avoiding Costly Automation Mistakes

Hi, I had the same issue a couple of times already: after setting up a list with waterfall/claysearch (with only 10 rows running to test), I altered the source and added new rows. Then all rows are run automatically, costing me a couple k of credit. There is no warning message, indicating that the change will cost massively, nor is there a way to understand how the change will impact the list/automation. Would be crucial to not lose a fifth of monthly credits by mistake.