Genuine answer: sometimes. I've done similar levels of reverse engineering. Keep in mind that LLMs, and all other AI, "think" as they are programmed to. When you need to do something they don't know how to do, because you're the first person in history to do it, it turns into a lot of hand holding. Especially when you're dealing with physical devices that can explode if misprogrammed, I've found it's best to keep them working on the lower hanging fruit.
Nothing is stopping you from using LLMs when contributing to their project (I think). One reason might simply be that they would rather spend the (very sparse) donation money on anything else but tokens.
They do currently ban LLM-assisted submissions. To be honest, even if LLMs are technically capable of writing code that assists the project, this at least helps keeps the 'floodgate' closed for certain low-quality PRs that other open-source projects are getting.