It's nice to have the baseline around, because now I have something to match the presentation of H3's with. The next version of WordLand will have that worked out.
Had to back out of the Styles panel of the Settings command, I did it way too fast, each feature it added had to be tested in this very particular context.
The context is Medium Editor, Markdown and WordPress. None of which were designed to work with each other. We're lucky to have a core subset that works, enough to support writers.
I think to get a really complete editor, you have to start with Markdown or HTML and work it out with WordPress.
I have made the style of H3 agree with the style of in the Baseline theme.