While it's possible to reference external JS, images, etc. in the variation code manually, heavier-load sites are more sensitive to something like loading an external JS. It'd be great if for external scripts and media (images, videos, etc.), Optimizely offered storage so that users could reference these things internally. I feel like this would be especially useful for people looking to test hero sliders without having to reference images on their own servers as some people working on testing have no access to their server(s).