In Absentia, at least as a CD, is mastered loud. If there is a DVD-A, that is the way to go. (Not as bad as Deadwing, but I prefer Stupid Dream, which I recommend.)
As for CD's being able to be mastered louder, such has not been the case, especially in the era of digital mastering. Incesticide, the Nirvana compilation, was digitally mastered, and sounded just the same on vinyl. Same for Memory Almost Full by Paul McCartney when it came out. Many artists, including Steven Wilson, and if anyone wants another example, the CDs by Big Black/Shellac/Rapeman (mastered by Albini) and Loveless, are quieter than most other CDs, but their sound has a force about it that makes it louder.
I must also add, Led Zeppelin isn't quite considered prog rock, but I can see an argument for their later years.