Actually it seems that TTT and ROTK will use the same master, which is OK because it was only FOTR that had a crappy transfer with tons of DVNR applied and that will get a new master derived from the 2K DIP, which is probably the best quality copy there is short of the o-neg, but that doesn't have CGI and colour timing applied to it.

And the films being split over two discs is actually great, it means the highest quality possible and switching discs doesn't bother me, as I like to make a cigarette break half way through a really long movie like this anyway ;-)