In many cases- how much of this current trend towards rockered XC skis is about deliberate utilitarian design, and how much of it is just a way to marketing trend- designed to re-market skis.
The Nordic rocker on the Ingstad and the E109 is the result of intentional design- to improve the downhill performance of distance-oriented BC-XC touring skis. The trade-off is a short XC glide zone on consolidated snow. The E109's problem is that the shovel is too damn soft and unstable (STDS= shovel too damn soft!)- making this otherwise wonderful hill-country XC ski miserably unstable in deep soft snow.
At first look, the major rocker on the Ousland ski seems an act of madness- until you consider skiing over the Polar icecap...The crust don't "break" up there and it can be piled metres high!

The rocker combined with an unstable soft shovel on the E99 Xtralite is just plain stupid. The ski is slow on consolidated snow and unstable in deep soft snow.
OH- but the Nordic rocker makes the E99 so much easier to turn! Really? It makes the effective edge shorter- sure. Perhaps it "improves" turn initiation- but it certainly doesn't make cambered and stiff-underfoot E99 a downhill ski.
So let's talk about the marketing BS.
Early-tip rise.
Skis with rockered tips offer early-tip rise-TRUE.
Narrow XC skis with rockered tips can take advantage of early-tip rise- bullshit.
Narrow BC-XC do not float high-enough in the snow column to rise up and plane when downhill skiing in deep soft snow. (I have let my 205cm Ingstad BC completely go and reached LUDICROUS SPEED a couple of times- yes they will rise up and surf at LUDICROUS SPEED.)
The rockered tip on the E109/Ingstad definitely improves turn initiation downhill. And with the tip already "bent" into a rockered geometry- a ski like this simply does not need an ultra-soft shovel- in fact, it needs the opposite.
Oh- but tip rocker improves BC-XC trail-breaking because the tip wants to ride on top of the snow! Bullshit. The tip does want to rise alright- it is rockered. But this does not improve trail-breaking- it undermines it- leaving the ski breaking trail with the shovel- instead of the tip- and leaving- at best- the skier in this perpetual hell of skiing up a virtual hill- at worst- if the tail is also soft and round- it delivers the dreaded BC-XC pool-cover syndrome.
None of these BC-XC/fjellskis are wide enough to float at the top of the snow column when XC skiing in deep soft snow and no one can XC ski fast enough for one of these narrow skis to rise up and plane in deep soft snow.
The best trail-breaking BC-XC ski I own is the Asnes Combat Nato (the USGI Asnes Combat a close second) and this ski has ZERO tip rocker.
The Gamme 54 with its low profile slight tip rocker, stiff supportive shovel, and traditional broad, raised tip offers about the best balance I can think of in a distance-oriented BC ski. It does offer some noticeably improved turn initiation, but the shovel and tip are rock-solid stable- supportive in deep snow; long glide zone on consolidated snow; and crust-smashing, trail-breaking raised tip.
The E99 and E109 are both terrible messes of the old-school-pre-tip-rocker soft tip of a BC-XCD ski; with an addiction to "more-is-better" tip rocker.
The E109 needs a stable shovel.
The E99 needs a stable shovel, MUCH less tip rocker, and a traditional broad-raised tip.
The photos of the Nansen are interesting...What little "Nordic rocker" there is, is very low profile... Do you think that is appropriately described as "Nordic rocker" or is it more the result of the shape of the tip and its transition into the shovel...What does it look like without the camber compressed?