Weird…
In my original code block I had both an icon point to a lucid string with, and another without, quotes. Neither worked. But, now that you’ve suggested it… it works. 
I did run into issues getting the ‘lucid-coffee’ icon to show up, but it eventually started showing up after I swapped a different icon in and then swapped it back. Maybe it was a loading issue that just needed a little encouragement, or Obsidian hadn’t had enough coffee. 
Thanks for checking into it!