After an omni is built in space, it starts to float and I can fly a different omni exactly under it.
Isn't that true for any Omni? Space Omnis are able to move freely past each other, as ships do? No landing or building on the same spot, but moving is fine...
Yes and no. You're talking about moving - every unit can move through every unit.
I'm talking about standing still and being in the same spot. You shouldnt be able to place 2 units in the same place, but freshly built omni doesn't prevent it.
My mistake... I had thought you were moving the upper Omni.