On what hill will I perish for pedantry?
The Oxford Comma.
Use it. Love it. Never relinquish it. No excuses.
In all fairness, my current copy editor is #TeamOxford too. When I worked in online publishing--where character count is king--the copy editors were not on this team. Ack. Wince. Grargh.
I love, love, love the copy editor I have now. She is worth every penny. 99.6% of the time I don't argue with her. It's "Accept Changes" all the way down the manuscript. I even surrendered to the idiom over the nominative use of "to be." (e.g. idiom = It's me. Grammatically correct = It is I.) She knows my style, works within it, and never tries to change my voice for the sake of AP or Chicago. Usually, if I ignore one of her edits it's because I've co-opted a "real" word for a fantastical definition.
We won't discuss the gray hairs I've given her over my Use of Capping All The Things.
Or my love of ellipses.
Or my abuse of hyphens.
One day, I'll win the "keeping semicolons in dialogue" disagreement, though.
Once I muster the courage. 😅