Oh ratfink! You can only do one image at a time with Dalle-3!:
You can request 1 image at a time with DALL·E 3 (request more by making parallel requests) or up to 10 images at a time using DALL·E 2 with the [n parameter]
https://platform.openai.com/docs/guides/images?context=node
Yes, I see the note on making parallel requests, but that means an awkward restructuring of my code to handle this.