I moved my appdata and system data off to the array and my nvme drive still had 155 GB being reported in use. Calculate space showed 800k, which there was some lingering appdata from my Plex server. Subtitles, meta data, etc.
I ultimately stopped the array, removed the nmve drives from the pool, restarted the array, stopped it again, adding the drives back to the pool, and restarted the array again. 3.5 MB was now reported in use. As expected with nothing on it. Still a mystery what was taking up the ~155 GB. The usage would change over time, as you can see through this thread.
