Sharing Course Development

How do you share Articulate Studio course development with a SME?

I'm an instructional designer who is looking for an effective way to share course development with a SME who has PowerPoint but not Articulate Studio. Currently, I set up the course template and send him a copy in which he can provide ideas for content (notes and graphics) which we use as a working document. Then I create the course in Articulate (Engage interactions, Quiz, etc.). I need him to review and approve the script before it goes to the narrator for audio. He wants to see how the course looks and how it will work, so I publish a copy of it (with a read-along tab in the player) to the LMS for limited distribution so only he can see it and read the script as he watches it. That way I can get script approval before it goes to the narration. The issue is that when he (and other reviewers) watch the course with the audio, they invariably want to make changes to the narration. This means several rounds of reviews and re-narrations until the course is approved for distribution. 

I'm open to any suggestions.