Thank you for the mention @gadrian

people who aren't paying attention when they define the rules

Several safeguards have been added to check typos in rules. Still, as stated in the tutorial and documentation, it's up to the user to double-check and test their rules with small amounts before relying on them for bigger transfers.

if an exchange account changed since users last defined a rule for that exchange

Once again, it is the users who remain in charge and it is up to them to update their rules in the event of a change on the part of the exchange.