I made a similar comment during the previous review. A nil tolerance is implementation defined. I think it would be reasonable for this to be customisable (environment variable? global setting?) to mean no tolerance for server applications and have the current behaviour for client apps.
[edit] I think the meaning of tolerance:nil would need to be a process wide setting, because otherwise a library using the default tolerance would have the wrong behaviour on one or other platform.[/edit]
That seems like a separate (but still important) issue to what’s in this proposal, which is just continuing with the existing behaviour.