Instead of this being just a side bar, I want this to be able to use Mobile version of a website (it can do this now... but) + the ability for this to be a a split window. I know this is currently an extension, but the whole idea about using this as an experimental extension is to see if this feature makes sense to be in Firefox natively right? I would want this natively in Firefox if it can work as a:

1. Side view exntension's current capability. Don't remove mobile website invoking capability of the extension. Amazing for testing and other mobile oriented experiences when needed.
2. If it can also work as a split window natively instead of having to rely on an extension.