No, I haven't, but right now, I do not see how one would reduce download volume by downloading packages and creating install media locally instead of downloading the media in the first place .. (?)
You download the needed packages once and use them to create multiple media sets, instead of downloading multiple media sets which contain duplicated data.
So what? The same holds for downloading the image files [(1 x "Core" + 1 X "Extras") / arch] and extracting packages locally at will to recompose them for a custom install class [At least if you feel the need to do so. Using an appropriate kickstart file would do the job as well without tinkering with the install media. So, I wonder what this spin frenzy is about]. This corresponds to the standard media as those distributed for earlier releases [albeit doubled by adding "Extras" now]. Moreover, this is the only way to make sure that you have access to all available packages after installing the system without relying on permanent and high speed network access. Btw, I think nobody ever asked for all possible custom or contributed install classes to be mirrored as "ISO" images.