I saw another thread that follows this topic. What could be done with Tomorrowland, with a billllion dollars?
Then this thread which I think deserves far more attention. Interesting Anahiem Resort Area Documents
And there was also this one. Autopia monster queue = One E Ticket
And my idea happens to cover all of those subjects.
To start I've mention this before and others have too that sight lines can be preserved. In DCA the Cadillac Range blocks out the Hilton, and Screamin Blocks out the convention center. The Hyperion Theater is going to block out the rising Ramada Maingate. A Western River Expedition or something like it on the north west part of ROA could Block out the M&F garage. And so my idea for Tomorrowland uses the same method.
In Tomorrowland specifically it gets taller as you go in. That is the parts facing the Hub do not grow, they stay their current height to not intrude on the theming of the Hub. However these building in the foreground do block the view of what's behind them. So behind them Tomorrowland Terrace and the Star Traders/Starcade building could be taller. And opposite them is even taller building where Innoventions and the Pizza Port are.
These large building can allow layering, multi tiers of attractions, or attractions that have vertical differences in their layouts. Also these building in their lower levels can go over, or accommodate into their structure railroad dioramas, and monorail tracks, and some back stage functions.
Also to create a clear divide between Fantasyland and Tomorrowland a triangle shaped mountain could be used. The back would face Harbor blocking site lines out of the park. One side would face Fantasyland the third Tomorrowland. This would allow for a wild part of tomorrowland, and another mountain for Fantasyland. These mountains could be just back drop like the Cadillac Range or accommodate attractions. The monorail, Autopia and Subs could be under or inside the mountain or replaced with other attractions.
A dual function of this vertical space is that it creates more space not just blocking site lines. As DL stretches to its max area the only way to grow is up or down. This will require the stacking of guest spaces. Tomorrowland simply allows for extra tall and tiered structures as its urban theme is natural for it.