This is a really cool project, I particularly like how well thought out the possible connections are between tiers. The only 'issue' I can see is that rooftops are often left inaccessible! Automatically adding some ladders or steps to adjacent would be a simple solution but I'm sure there are more imaginative and architecturally inclined people than me with better ideas!
My creation: https://i.imgur.com/fwR4E1P.png