We're beta testing serving your shared projects over https with http2 enabled. This mostly means that your project will load way faster. You can try it out by just changing your share links from http to https.
The downside is that if you use external resources (images, scripts, fonts, etc) from a different domain, they have to be https too or your project might fail to load. This is only a problem for ~1% of the projects we see.
The best way to make sure you always load resources the right way is to change your urls from "http://hello.com/script.js" to "//hello.com/script.js". It will then pick whatever the current page uses.
For a cool demo on http2: https://www.cloudflare.com/http2/