No, it is you who missed the point of the GM release itself.
And its far far easier than that to install the GM on a device running the Public Beta. Merely delete the Public Beta profile and install the Developer Beta Profile and bingo, you're seeded the GM like every other Dev.
[doublepost=1473341420][/doublepost]
Is public beta enrolment closed? I've been running it on my iPad Air. Confident enough to install it on my iPhone. Doesn't seem like there's an option to install the profile from Apple's public beta site.