I write fiction in multiple settings and multiple genres and having the wordlist located in a central place per machine means the wordlist for one story gets merged with all of my other stories. The trouble is I don’t necessarily want to do that. Genres like science fiction and fantasy can sometimes mean a word that’s a legitimate misspelling in one document could be someone’s name in the other. Not to mention this would help solve a complaint of wordlists not syncing across multiple devices.
Have you tried Project > Auto-Complete List ? Usually I only play with this when writing a screenplay/script but it could be used for other projects too. Failing that you could try File > Compile > Replacements to force what you want into the final compiled version of your project.