Aaaaaand I figured it out. The 'wysiwyg' field returns an object, so to call it, it requires:
{customContent.additional.html}
Which I discovered because the docs mention that you can append
?format=json-pretty
to your URL and it will output all of the page's JSON for debugging, which was incredibly helpful. So your URL would be:
http://www.mysite.com/my-list/?format=json-pretty
Hope this helps someone!
👋
SquatchCreative's post in Output a WYSIWYG Custom Field added to a Custom Collection was marked as the answer
