I write a lot of fiction/fantasy/poetry, as well as play around with neopronouns (eg: xe/xyr), and while I can click 'ignore' on the spelling or grammar check, it inevitably comes back when I change chapters or open the project again a different day. It would be amazing if I could, for a project, 'accept' a word or phrasing and have it not be flagged again in that project.
I'm working on one now, and the main character is currently using xe/xyr pronouns, and it's a bit difficult for me to sift through all the red marks when I'm trying to find an actual mistake.