> Though I do note that when I type U+1F928 FACE WITH ONE EYEBROW RAISED in a title, in the app’s sidebar and top-of-page title it becomes U+1F929 GRINNING FACE WITH STAR EYES. That’s… not encouraging, but ultimately presumably Just a Bug.

Fun discovery: this is a Firefox bug. Address bar, text areas, &c. and it’s consistently rendering the wrong character, but somehow your canvas got it mysteriously right. Wild! I should update my Nightly (couple of weeks out of date) and see if it’s still happening, and file a bug report if it is.