Is the DLC volume limit regulated by Sony? I am downloading my missing itineraries because of the 64gb limitation, at the moment I am at 94gb and everything is working, as soon as I have finished downloading everything I will let you know (I have all the dlc and add ons available).
You can download over the 64gig limit but it won't show anything past the 1st 64gig, it is regulated by Sony and would have to be changed in a system patch by them to remove it, or do a work around as the devs are currently working on.