I know the question wasn't to me, but I will put my input regardless
Just finish playing my second game on hyperspeed(didn't finish the first game as it was more a test after coming from like over a month break from Aurora):
There are few problems I have, but one of the main ones for me remains the balance and lack of challenge i guess - Currently even on the Extreme diff and galaxy aggression on Chaos, you easily snowball the game the moment you reach the cruisers and tech tier 4 or so, most AI cannot handle that level of firepower and you just win the game in most cases there, even when you start on harsh which will put you back at the start, but if you play on 1000 stars 10x10 and 10 AI, usually your development is not disturbed for first 2 tech tiers and that is enough to beat any obstacles from harsh start, the next thing is that AI seems to not be able to handle to start on higher tech level(fair enough I haven't tested that in a while, last time it was pre Aurora so maybe something has changed, but in my experience if they started on tier 2 it took them absolute ages before they manage to do anything) — I know Erik spoke on stream that they still work on the AI as their goal is that AI is smart not just get the typical yields cheats, so definitely something I'm looking towards(in my experience I think the problem is how AI managed their research, in my 2 recent games most AI have building the special science building very early on when they barely have frigates and tier 1-2 weapons researched but tier 4 in research part of the tree and there is more examples like that), also the other things Erik mentions like re-balance of all base faction and improvements to hive, sounds very promising
The next big thing is ofc the endgame threat and again I know Erik spoke about which will happen with Shakturi Expansion and hopefully that with AI balance, faction rebalance and expanded Hive will resolve these problems as that probably the biggest things for me in terms of replayability.
There is quite smaller grips such as some visuals design(many ships features for base game races looks poorly for example human railgun is just long stick compare to cannons for dhayut or quite few rare ships model that can be found to repair)
Things like UI elements especially around colony details screens, also the lack of good description for many things(Big shout out to Scott for his test and guide for things like difference between PD, sensors etc)
There is also number of areas when things are working, but they very limited, like main story, events, ancient ruins, debris fields etc - I would love to see that expanded more in terms of actually so kinda excavation work or more complicated/longer events that require few things to do and that your tech level etc really matter
Same thing with technology, i love the huge tree and the choice, but in many games it becomes more hindrance than a good thing, good example here are Engines(you need to research 3 paths of 3 lvl of engines to get to vortex which at the point of research are barely any better than previous tech, instead of just following 1 path to unlock vortex) what i'm trying to say here is that i would like to either see mutually exclusive paths or done in the sense that early you have less option and more in mid/late game for example such as getting 1 type of engine in early game then 2 possible paths in mid game that you can only need to research one to get 3 late games engines which are mutually exclusive(or simply very expensive to research which make sense to just follow one), i feel that it would increase replayability as currently it feels that you just use best option and research everything else to tick the box to get higher tier and ofc not every component have to be this way, some are perfectly fine especially around weapons.
Another thing is terraforming - on paper neat idea, but in reality the second lvl of the tech is unlocked when 95% games are already decided, I would love to see to be able terraform planets that aren't colonize of maybe option to make small outpost that will have option to change full colony once the terraforming process is done and bringing tech maybe tier earlier or that whatever your species are desirable planets that tech for tier 1 is already unlocked and you can let say research tier 2 option relatively easily.
Another problem i had with both aurora and hyperspeed (which already improve that a bit) is resource transfer between bases/colonies etc, i my recent game it took 10 years for planet(3rd planet that I colonize like 60 years in game) in my home system to receive resources to build a tier 2 space station and despite having 40 fuel tankers and 3/4 sitting with no mission(and having 2000k of surplus of caslon and like 200 net positive mining rate) i had a lot of stations etc with 0 fuel on it.
I would probably find another dozen of things to mention, but i really believe that DW2 have a great potential and hyperspeed compare to release is like 2 different games, but currently, for me it's game type that once you learn how to play it becomes very linear experience and take as lot of the fun part of the game.
Open to discussion guys and would love to see your insight.
P.S
sorry for that essay and any spelling mistakes

(english isn't my first language)