Oof. I just checked out flycat.club. That's not the prettiest sight. I'm sure they'll build it up over time. I really like the way yakihonne.com feels and works for long form. It doesn't let me see notes unless I'm on my phone but It's been my favorite for writing as the format doesn't shift between the editor and post.

Freerse is pretty sweet too. They've rolled out some really cool features for long form.