There was a bit of a tiff between Bethesda and Sony over Skyrim: Special Edition when it came to mods. First Bethesda announced that Sony and them hadn't been able to come to an agreement, so the feature would be absent in the PlayStation 4 version. Then it seems an agreement was made, with Sony agreeing to let mod support come to the console version of the remaster, but that it wouldn't be able to important external assets.
Well, it looks like the PlayStation version is going to have another pretty serious short coming. In an FAQ it is revealed that while the Xbox One version of the game will have 5GB of storage for mods, the PlayStation 4 will only have 1GB, Now, obviously, by not bringing in external assets, space should most certainly be saved that way, but it is could end up being limiting for some.
It appears Sony are being very careful with what the allow onto their system, possibly to a fault. They've chosen to not allow EA Access or Early Access on their platform either, which is something Xbox has embraced. It seems if you want the best version of the Skyrim rerelease, Xbox is your bet.