I think there are some inherent limitations to the ICE or combination platforms, such as
- Hood length
- Driver seat placement in length-direction and visibility
- Openness of cabin area
- Potentially lower center of gravity
- Rigid batteries adds to strength, perhaps allowing for weaker frame constructions giving more space and saving money
If not careful with these differences, there are some design traps to fall for.
For example, fitting all batteries of a >80kWh car between the two axles on a flat floor gives either A: a very tall car, or B: a very long car. The i40 isn't especially tall, and not especially long either. Using the prop shaft tunnel to store batteries has probably been beneficial to keeping the proportions as well as the balance. COG-wise it will be slightly worse than if it was all flat, but I think the effect is minimal.
A lot of EVs have embraced the flat floor solution, but I personally think the normal BMW design of having it not so open is good, especially when that space comes to use.
I don't know how overview will be in this car, probably okay, but the overview you get in the front in a Tesla Model 3 is really good, it's very easy to maneuver.
I don't know to which degree they have used the battery as a structural element in this car, but it looks like a carbon copy of the 4-series GC, so I would think not much, or at least they haven't changed anything else. This will add to the weight (but make it stiffer, of course).
It doesn't have a frunk, but it looks really structurally rigid there, and I'd rather have that!