I guess I just assumed that if your top-level functions were type stable, then your closures are also very likely type stable. So individual functions are a good “atomic unit” for debugging things.
And if only the closures themselves are unstable, but not the function, then the closures probably do something that isn’t important, like log debugging information or something (which wouldn’t need to be type stable anyways).
But if people want I could change that. I just thought it didn’t make much sense (but I welcome arguments otherwise, I just can’t think of any!).