Hey @matthill! In addition to letting our current constraints guide your creativity (definitely something to be said about that!), I wanted to add that we do plan to add support for templates and modifying HTML in the future.
This is part of a new initiative to make Write.as more flexible and useful – the templating system upgrade @kxra mentioned earlier in the thread (development tracked here). We’ll keep everyone updated as we make progress there in the coming months, but I’ll be especially interested in feedback from professional designers like you guys as that evolves.