Thank you for the discussion so far, guys; I appreciate reading interesting ideas and different point of views. I will just add my humble opinion on the matter (with reference also to the developer/pro laptop topic).
If Eve will start a new project/(s) after the V, it makes sense in almost every way that they try to differentiate the new product from the V itself. On this premise, a tablet with "small" 13'' screen size (for a laptop! 13'' is plenty large for a tablet, if you ask me) and differs from the top of the line V-i7 basically for processor power available and dGPU for graphic performance is arguably quite similar to the product Eve will already be selling.
Please, also consider price guys, never forget about it: the V-i7 was sold for $1399 on the IGG campaign: an amazing price point compared to competition, but by no means little money... The kind of device you have been describing would cost more...
List prices MSstore .de (Germany), as of March 2017 (I know you can find better prices in other places, it's a reference)
- Surface Book, i7/8Gb RAM/ 256Gb ssd /dGPU: 2.319 Euro;
- Surface Book i7/16Gb RAM/512Gb ssd/ dGPu: 2.919 Euro;
- Surface Pro 4 i7/16Gb RAM/512Gb ssd 2.329 Euro
Going for a bigger screen, likely industry standard 15.x'', would instead completely change the class of the device. At this screen size, I think that most people would find it awkward to use the device as a tablet. I am not saying everyone would/should feel this way, or that I criticize those who would take advantage of a very big tablet... Lets just agree that heavier and larger tablets are niche, as of today.
Also, dimming the spotlight from "tablet mode" (community could discuss of potentially ditching it completely or maintain it with something like a 360° hinge / convertible) would mean design advantages in almost every other feature of the device: power, performance, complexity of construction and... price!
Basically and in fewer words, I think that if performance is to be the number 1 feature goal of the device, then the pure tablet form is a limitation and classic laptop form factor more suited.
Instead if performance / pro user usage is not really the main goal... well, if Eve really develops an eGPU solution for the Eve-V, then performance differences would be even thinner (I am not saying nonexistent, of course), since the V-i7 is already powerful enough for many computational tasks.