1Dot there's a recent discussion that talks about some of this here https://discuss.flarum.org/d/27814-embed-discussion-in-a-different-page-solved/22
The only "feature" embeds give you for better integration is the iframe-resizer library.
Any further integration to look more like Disqus for example will require a lot of work, which is why this wasn't done for Embed because it's a secondary extension.
If you work on a more integrated look for the iframe, we'd be happy to integrate the changes into the core extension.
I am planning to do something similar for my Wordpress comments extension because it's a popular request, but I likely won't share the implementation as open-source, partly because some of it will be Wordpress specific, and partly because it's a big feature and it's worth being a paid product if done well.
