I love quoting, and I love bookmarklets! 
A few years ago I began working on copying stuff into Discourse for archiving/discussion (archiving in this sense is similar to copying images, for both privacy and historical reasons).
Anyhow, my first attempt worked for me at the time: https://talkgroup.xyz/t/discourse-has-an-api-for-updating-single-topics-adding-messages-etc/2557/6?u=maiki
<a class="bookmarklet" href="javascript:(function()%7Blocation.href%3D'https%3A%2F%2Ftalkgroup.xyz%2Fnew-topic%3Ftitle%3D'%2BencodeURIComponent(document.title)%2B'%26body%3D'%2BencodeURIComponent(location.href)%7D)()">talkgroup (as a verb)</a>
I’ve improved on it… but as a relaxing hack in a browser where I didn’t save any of it…
@jimkleiber let me know if you come up with anything, I’d try it out! 
Bringing up “quote anywhere” and Wikipedia in the same topic made me think of my favorite thing on Wikipedia that I wished were implemented at the browser level… but likely greatly modified to allow for privacy issues.
Anyhow: Wikipedia Previews!
- Wikipedia Preview - MediaWiki
- GitHub - wikimedia/wikipedia-preview · GitHub
- Wikipedia Preview – WordPress plugin | WordPress.org
- How we designed page previews for Wikipedia — and what could be done with them in the future – Diff – great background
Imagine using that, but with oEmbed/OpenGraph/Onebox support, so Discourse does the previewing!
(This isn’t a different feature request, just sharing to ideate better bookmarklets. ^_^)