You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
It is unlikely anyone inside Tesla has all that accurate a picture, either. At this point they'll have a very modestly more informed guess, that's all. That'll change over time, as the internal data accumulates.
They'll gather data over months and evaluate reliability, probably on a rolling basis, watching for any clues about edge cases popping up. The more data they have that we all don't the greater the difference in understanding of the actual release date, and the feasibility on the different potential specifics of the features.
I'm trying to recall how long it took to go from "tap to accept" to allowing the option of fully automatic lane changing? I can't see how this will be any shorter a period. Especially given the potential of cross-traffic and other obstacles popping up at green lights.