It’s remarkable this still hasn’t been implemented nor that it wasn’t originally. Adding a class and other options is futile. The DnD system needs an overhaul entirely. It’s just simply not good - nor will it be until developers have actual flexibility and the ability to integrate fully with it. This means 1) opening up styling definitions per module updates and 2) expanding style fields and other fields to be free form. As always, swing and a miss.
The amount of bloat - particularly with styles - is ungodly. Utility classes anyone…? And OP actually missed the most obvious use cases for classes at the section level… Thematic encapsulations of surfaces and elevations. Speaking of responsiveness… It’s impressive that “feature” was realized roughly 1 year ago with “more options coming soon” for responsiveness and it’s still in it’s incomplete state. Not that it really matters - it’s a poor mans way of doing things.