You are right about the lift, Planeshift isn't advanced enough for a working one yet, i think.
The Vegesimi lives on top of the tower, i don't think she would enjoy climbing up and down ladders. She is the most important person in the city ;P and would have to move around her quarters by ladders? ;) (I mean these inside the upside-dpwn pyramid.
I think in rl the side towers would be used for ease of transportation and defense. In game, one can reach the spots in the towers using the main staircase and dropping down lvl by lvl. Also, ladders would have less polys than two more staircases. Again, what would you suggest?
So, their only purpose of the two side towers is military mobility in case of the tower siege and transportation of stuff by the ladders? It is extremaly hard to carry stuff climbing the ladders at the same time, unless you have backpack, but then you can't put much inside...Ladders are good for mlitary, but this isn't defensive structure at all. It is the most magnificient structure in the whole city.
So yeah, the towers can indeed have a little use, besides big impression and platforms for gliding down Klyros. I think i would be much more satisfied if the tower was about something more significant too ;D, maybe someone find out something later and we can reflect it in their architecture.
Btw, who said it is the knowledge center? ad there has to be some books sculpures on top of it? I couldn't find it anywhere in the city description. Where is it?
So what i propose: A steep 55
o wooden stairs. Their face count will be probably the same as ladders. But here is the trick: Buildings has this advantage that there is no way you can see all its parts at once, you can't float above for better viev like above a landscape/city. You see only small % of all the faces and only this % is computed at given moment, at least i think it is how it works.
Also, read the descriuption again, you missed some details, including proportions
I made some concept image for the at 50 meters height cavity.
Oh, i ben wondering too how the Megaras sleep ;D I came to a conclussion they are too big to find enough good places to sleep upside down, and so they would sleep normally. Besides, if they didn't, the stables would have to be very high, so they could fly in, rotate in flight and hang to something on the ceiling ;D
I think the stables should have enough room for their wings ~10m wide, when they want to spread them to relax muscles. So the stables can have a lot openings to fresh air, so when they spread their wings, they would reach outside the stables. I wonder what these Megaras would like more a cave looking stable, or wooden, like for horses :s funny, mysterious mutated bats ;)