No the 3 hour cut uses all the footage that was originally cut from the theatrical version, although they were mostly filmed back to back the extra scenes are relevant to the first film and you can see why some of them were cut.
The Donner Cut uses all the footage that was mostly cut from Superman II due to the reshoots Richard Lister had to do to get the directors credit.
I very much doubt we’ll get extras on par with the Blu-ray releases, my advice would be to get the TV cut version on iTunes and try and hunt down the Superman Anthology 8 disc Blu-ray set as the special feature in that are fantastic, it’s filled to the brim with them. And when I say packed to the brim, every disc has special features on them.
The Superman Motion Picture Anthology 1978-2006 [Blu-ray] [1978] [Region Free]
https://www.amazon.co.uk/dp/B004MYF6YK