I'm not necessarily questioning what Nord has to say about the extra work, but looking at D:OS, a lot of the groundwork is there already for an over-the-shoulder or even first-person view: IMHO the textures are "good enough" and it already features quite a lot of rugged terrain that would break up or indeed totally obscure distant landscape. It seems that nearly all first/third-person games seem to take place in a sort of "soup bowl"-styled world with large mountains and cliffs surrounding it, with odd bits of vaguely-defined landscape in the distance where it wasn't totally obscured: Ego Draconis being a good example of both. I was just thinking about the way Cyseal was designed and was wondering how much extra effort would be required to make it look like a convincing world when you're actually down there rather than looking down from above. Probably less than it would take to fill in the empty-looking areas when the 360⁰ camera was enabled (and which I think few if any people actually complained about).
Talking of terrain maps, I'm still bemused that the Sims series went from hilly in Sims 3 to completely flat in Sims 4, which seemed bizarre. I admit I was reminded of Sims when I was exploring Verdistis just now.
