…just to follow up. My Nanoleaf bulb arrived. Eventually I was able to add it to the same Thread network as my other Thread devices. The Nanoleaf app provided the bits necessary to create the TLV dataset using the python script. After adding the dataset to HA I was able to set my preferred network. Getting closer.
At this point I still couldnt pair HA with matter devices. Another post had me check that HA had IPv6 enabled. It did not. Settings/System/Network enable IPv6 was the final peice of the puzzle.