That risk assessment depends on your use-case. Those percentages also aren't very correct. Assuming that new files are being constantly created and they're not

That risk assessment depends on your use-case. Those percentages also aren't very correct. Assuming that new files are being constantly created and they're not of vital long-term integrity, the chance of preventing silent bit rot (ZFS is supposed to protect against) is worth fuck all if it's much more likely that a bug takes your pool irrecoverably with hours of data.