I disagree that it's at all feasible with CryEngine. It's an engine that's specifically designed for FPS games in small-scale maps connected by loading screens, and CIG have already had to spend 18 months re-working it to support the larger maps they need by changing it to use a 64bit coordinate system, but this still doesn't address the core issue of it not being a suitable engine for doing 1:1 scale space games.
IF they had planned it up front and IF they had chosen a more suitable engine (or written their own), then they MAY have been capable of doing a 1:1 scale game.
Again, it's an entirely moot point as that is NOT what they are going for.
I really don't know why you think it's not feasible with cryengine, seeing as it is in fact perfectly feasible on cryengine (go look up the segmented worlds feature of cryengine). And saying that the engine is designed for small-scale FPS style maps, is a bit silly when people have actually been making large MMO style maps with it (Aion, ArcheAge, Asta). The maximum map size without segmented worlds is 256x256 km if I remember correctly (although it not really usable).
You could do that, but you would need loading screens between each map, which would be a bit rubbish in a flight game to be honest.
Not only could you do that, but you can also do it seamlessly without loading screens, which coincidentally is exactly
what SC is doing.
Have you used CE before? No. Didn't think so.
Segmented worlds, or "Map Streaming" as it's actually called in CE, comes with it's own limitations. Basically you end up with a whole bunch of tradeoffs that result in you having to chose where to place the seams - as you still have seams. Yes you can stream segment content ahead of time but you can't make all of it visible ahead of time.
It's also peculiar that double precision isn't being backported. Allegedly CIG did this task in a few man-months - which is nigh impossible considering that they'd have to adapt physics, networking and tools. Heck even the spatial audio stuff is affected by this. Maybe they just hacked something together, I dunno. But judging from the fact how many people don't know the difference between a 64-bit executable and double precision math, I wouldn't be surprised if they'd just make up claims. You won't know the difference anyway, remember? They're not simulating the proportions of planets anyway. It's just a sphere with a few dozen km in relative size.
Not that any of this matters because AFAIK map streaming is not available yet, and if you do double precision you don't really need them anymore. Map streaming was hinted at for 3.8, but we're at 3.8.3 now and no sight of it yet. The thing we get to use is called Layer Streaming and it allows you to segment one big CE map which is too complex to handle into smaller manageable chunks, and is basically meant to be used to optimize games that are just too heavy for consoles to handle. It's a pain for the map designers because for them to properly test their layer definitions, they have to run the actual game binary instead of being able to just try it in the editor. So generally it's much easier to just optimize the map as a whole and make it the same for all target platforms. At the end of the day you still run in the same coordinate system with the same limitations: You either run into the map size limits (8192x8192 AFAIK, but correct me if I'm wrong), or you scale down your actors to the point where lack of precision screws up physics and collision detection.
I never said that there wouldn't be potential issues with making an infinite maps (or a 1:1 scale galaxy) within cryengine, merely that it is technically possible (unlike what Mu77ley claimed), either way I'm not really sure how you can claim so authoritatively exactly what the strengths and weaknesses of the segmented worlds feature is, since as you said you don't have access to it yet (segmented worlds isn't in 3.8.3 because it isn't part of the EaaS version, it is only available to licensees like CIG). Either way, yes I would imagine that the segmented worlds feature would have potential issues with segment transitions, but that's probably the entire reason behind CIG moving to DP, so that they could make the segments large enough that transitions will be sufficiently rare. Whether or not you need segmented worlds or not with DP is debatable, CIG is allegedly doing 1:100 scale and if we count the solar system as having a radius of 100 AU (rough end of heliosphere, and the aphelion of Eris), then CIG would need a map size with a radius of 1 AU and a diameter of 2 AU, 100 million km is only 0.67 AU, or about a third of that (8.8 billion kilometers would be almost 60 AU and as such more than enough), so they would need 3x3 segments to cover the solar system (I doubt anyone would want to fly particularly far out of plane, so one segment along the z axis should be fine).
Also layer streaming is not really the same as segmented worlds, as layer streaming is really meant to do more within one map, not seamlessly transition between maps like what segmented worlds would allegedly allow. And as you said it's not particularly easy to work with since you have to more or less manually define your layers in an optimal manner. And yes I think 8192x8192 is the practical limit with MPU set to 2, although you can in theory set MPU as high as 64 (if I remember correctly), giving you a map size of 262km x 262km, although it's not necessarily the most stable thing in the world.
And SC most certainly does simulate the proportions of the planets, or at least some of them (the gas giant in the multi-crew demo was some 180,000 km, if I remember correctly).
The only loading screen is the hyperspace jump sequence. That's not too jarring (and is perfectly understandable)
You also have a "loading screen" when you drop out of super cruise and when you do an interdiction. Basically Elite has plenty of "hidden" loading screens.