For what I used, the code is organized and works, so thumbs up for that. The only thing that is missing is a simple screenshot of the pool/dataset layout that your guide is based on. This would help illustrate the design for the inexperienced FreeNAS users. Perhaps doing so will provide the clarity that others are seeking.
Just retired, one of my first projects is to streamline the wild grown family's infrastructure. After soldering a 100 ohm resistor into our Synology DS415 to get it running again my confidence in that system was broken and a proper NAS had gained top level priority. As a former DEC system engineer I was really pleased to read this guide. I am convienced, that a lot of problems we have today have their root cause in hastily assembled systems that got over the counter without any testing. For me it's kind of Zen to get the system a little bit matured before I put my life in pictures on it.