After posting this many blog posts with Quill's HTML editor, I've been somewhat annoyed at some of the strange HTML artifacts it creates. Specifically it adds a few helper classes to the HTML for some of the visual editor parts, and some unnecessary classes are added to some of the images.
Today I cleaned up the HTML that Quill sends so that it now only sends very plain and simple HTML. To do this, I send the output from the Javascript editor through the HTMLPurifier library, removing all class attributes and allowing only a specific subset of HTML tags.
This ends up being only barely visible, but is a good change under the hood. The one visible change this will have for my blog posts is that now they won't sometimes have an extra empty line at the bottom. This was caused by me pressing "enter" after writing the last paragraph, creating an empty placeholder paragraph in the visual editor.