Hi, just a small contrib, maybe not exactly what you need, but you may also consider HTML Editor plugin @ Market.
It also supports User's Description integration (with minor theme code change), and it also supports adding instagram posts, twitter single posts & timelines (feeds) directly into editor.
You can see demo post on my website (
http://osclass.work/for-sale/dvd/html-editor-embed-test_i86) and also give it a try (no account required). So, each user can input/embed posts from them into their profile description (for example), or even items. Re Instagram, no feeds are shown, not sure if this is a limitation of Instagram itself.
Still, I agree that from simplicity point of view, code integration, flexibility, maintenance etc. a dedicated plugin is definitely more convenient solution. I *had* to add support for this in editor as some users requested it... Also, some themes are badly designed regarding user's profile space, they move info into tiny narrow sidebars for some reason (to make more centered space for items), and that does not look so well on desktop. But, that depends on the theme, thankfully they are unique cases.
Regards
dev101