That's what Isaiah's speech therapist said he is now: 100% intelligible. All the speech errors he makes now are "age appropriate". He still has a "frontal lisp" which makes "things" become "fings", and he still drops the end sound sometimes which makes that "fings" become "feens", but apparently that's OK. I asked the therapist if that meant she thought he didn't really need to be in speech (because, frankly, my life would be a whole lot easier without speech therapy twice a week) and she said, "Oh, no! Now that I've got him in the system I wouldn't dream of kicking him out! You worked hard to get him in and I'm gonna keep working with him and helping him. We'll talk again soon at his next IEP about next year, but for now we'll just keep working." And I like that answer, crazy schedule or not.
There was a point in the past when I went to sleep dreaming about Isaiah on his mission stuttering out a few words at a time and really struggling with each word. I dreamed of mocking classmates and isolation and a hard life for him. Because "they" said he might never speak or that if he did it would be a struggle. I'm so grateful that they seem to be very, very wrong.
So this might not be the end of our speech therapy days, but it is the end of my bad dreams - at least about this one thing.