Hi all. Is there a way to turn on a full HTML formatting toolbar when editing a “formatted note” or “HTML Page”, so that I can set paragraphs to be h1, h2, blockquote, and so forth?
Currently, no there isn’t, though you can hand-edit the HTML in an HTML document, if you’re so inclined.
Thanks for the reply, Jim. Does DEVONthink have a plugin mechanism, so that I could maybe write a plugin to allow the use of a good JavaScript HTML editor—something like QuillJS (quilljs.com)?
Sorry, but no there’s no plugin architecture for things like this. It’s an interesting concept though. 
Oh well. That’s a pity. It seems a waste to store notes in HTML format but not take advantage of the basic features of the markup language (may as well just use plain text and save the space).
Thanks for the responses, Jim
–Dan
All of those formatting options you’ve listed are available in markdown, which is natively supported in DEVONthink and could easily be punted out to an HTML file if needed.
Amen, brother! 
Any editable document in a DEVONthink database can be opened with Data > Open With, or from the contextual menu, or by adding the Open in External Application command to the toolbar. Your favorite HTML editor is a click away. Rather than DEVONtech going down the thankless, slippery slope of trying to make editors that suit everyone’s druthers, IMO it’s a better approach to provide quick and simple access to the whole world of macOS applications.