There's research that supports invented spelling as a good tool to support typical learners. I think this another but more subtle gifted versus mainstream issue. For typical learners with layers of slowly evolved skills accumulated through repeated practice this makes sense as the process used to discover phonemic rules involves some early mistakes to build to future exceptions.
The process is lock in the basic concept then add the exceptions. Just like kids who add -ed to every past tense word or -s for every plural as a natural phase.
Now if my DS who pattern matches and makes confident guesses at words has no immediate correction, he is going to near-permanently remember his misspelling. And those are hard to unstick.
