Leaving Fear Fall while removing Carnage Warehouse and Storm Force is about 55k sq ft. Taking out Fear Fall bumps it to 71k. Toon Lagoon Amphitheater is about 56k sq ft.
The entirety of the Spider-Man show building (full queue and extended queue) is about 83k.
CitH = 42k
Mummy (minus extended queue and store) = 66k
Gringotts = 72k
MiB = 75k
Forbidden Journey = 73k
F&F = 68k
The thing is, they wouldn’t build a ‘second Spider-Man.“ They’d build something different, and would optimize space. Multiple levels are becoming the norm, and could allow impressive rides in much small footprints.
Transformers takes up 34k square feet.
They have room.