I ended up adding #gnome alongside. I'm vibing. I can't figure out how to get Geary to be dark themed like everything else though. I found a few posts but none of those worked. I feel bad that it's stuck on GTK3. It's way more responsive than Thunderbird has been for me. #Geary does have a wonky setup. For STARTTLS to show, you have to submit first, fail, and then it appears.