Manual wall and roof height adjustments: Being able to freely drag walls and roofs up or down instead of being stuck with pre-set heights would be a game-changer for architecture.

Freer wall placement (smaller grid): Getting rid of the strict 1-grid-square limitation for walls and letting us snap them anywhere just like furniture would fix so many detailing headaches.

Better lighting reach: Fixing the lighting physics so that ceiling lights in double-height rooms or second floors actually reach down and illuminate the lower floor properly.