Thanks for sharing.
I suppose the Sri Lankan method you described makes a bit more sense compared to the Thai method, as it uses less thread (and less time). I always wondered what the use of the kusi strips was, as it seems a lot of work for a tiny bit of robe, but perhaps they were originally the seams, as you illustrated.
You reminded me to post a small update in my old thread: Early monks' robes. Might interest you.