This was on the back-burner for a while, but we now added these two features:
Here’s what this one
a quick prompt that tells you how to leave the full-screen mode “Press esc to exit.”
looks like
And here’s what this one
add the + create topic / reply buttons to the full screen mode. If title/category/tags are missing, we force the composer to go out of the full-screen mode. You’ll then see the errors.
looks like
If the user creates a topic/reply that doesn’t meet the minimum requirements for a given site setting (title too short - body too short - required categories/tags), then the composer will go back to the default view, and they’ll see the errors they need to fix.
If the composer doesn’t have any errors, they will be able to post from the full-screen mode as expected.