D.B.
I don't understand why his speech would keep him in K. If he is doing the work, understanding instructions, reading, I see no reason to hold him back. Seems a speech therapist can just work with him on that aspect in 1st grade as easily as K! I've never heard of anyone born with 2 uvulas before, bless his little heart.
I homeschooled for many years and there is no one that will ever convince me that parents working with kids at home doesn't help. The ones I see now in my sons PS that struggle are usually the ones where the parents aren't involved. You can always tell which child has a caring parent at home! So continue working with him, it is making a difference.