For what it’s worth, here’s what I ended up doing:
-
On my blog, I have a
<div>with an id offorum-excerpt, which is hidden withdisplay:nonebut contains the HTML that I’d like to show in the Discourse post. (I do this using some Jekyll / Liquid logic, but that shouldn’t really matter.) -
On my Discourse, I set the
CSS selector for elements that are allowed in embedsto#forum-excerpt. Although the div is hidden on my actual page, the content shows up on the forum. -
I also uncheck
Truncate the embedded posts. -
In the
Embedded CSSsection, I give.buttona larger font. This is a small change but it makes the button to add a comment bigger. -
I have also customized the
embed.continue,embed.start_discussion, andembed.imported_fromtext, which changes what shows up in the comments section on my website.
This means that I have full control over the HTML that shows up in the forum post. The HTML I give it is basically the equivalent of a OneBox- it’s a big thumbnail and a link to the main post.
This works pretty much perfectly for me, belated thank you for the help!