I stumbled several times already due to typing ‘/’ in the quick add task panel not giving me the extra formatting options that I know from the regular details pane. Circle in the screenshot below marks the spot where the extra formatting options are located in the formatting popout of the details pane.
And on the topic of ‘quick add task’ feature completeness, here’s a shout-out to another request I find both very valuable and utterly undervoted: Need ability to set Tags via Quick Add Task