Indeed, requiring t2 air and a t2 transport makes it a much more costly option compared to the benefits (edit for clarity: this is GOOD. Otherwise the benefits FAR outweigh the costs).
If we enable this, there will be a new meta of going t1 and rushing your ACU to strategic locations... and also rushing inties to snipe opponents trying to do that. Games will end quickly with little strategy beyond "I got mid mexes first."