I'm not sure quite how that works. Google Docs will suggest various changes which I take into account or don't. And they certainly correct misspellings. You can choose to decide that's not AI but it's a grey line.

For writing I've sometimes used LLMs to speed up some essentially boilerplate. Never used for something that's not pretty much routine that I could easily do but would probably spend some time doing so.

For anything that might be a Nebula submission, it's hard to imagine LLMs doing anything beyond the copyediting level (which may not be well-defined but seems a reasonable threshold).