I’m a course developer on a closed-access learning platform for a year. I love slip and have been following you from the beginning.
I think import/export in Markdown would be a killer feature, in particular because it then makes things super easy to synchronize with GitHub, which is a must to version a course. And also, it enables to collaborate easily.
Does the editor enable collaboration? I mean, more than one writer?
A low hanging fruit maybe: may code blocks come with already loaded, popular code formatters / linters? And also text blocks with spellcheckers? I think this would benefit the editor.