I’m not sure if you’re still looking for an answer here but I’d make the mesh at full scale in the modeling tools, then figure out how many sprites at what size you’ll need to get the intended result, then use the Align Sprite to Mesh Orientation Node.
Also it’s important to note that what he said above about it needing to be in the particle update section is important. Certain options are only going to show up if they’re available and they can require you already have the nodes and be in the right section.
Whenever in doubt you can always check this guys YT he has videos explaining everything: