Hi Niven,
Thanks for your purchase and your kind words!
The subway station environment uses tiling textures so combining their maps would interfere with the tiling pattern. So the floor must have its own repeating square texture as do the walls, the ceiling, etc.
Is there a reason the entire environment should be on a single texture map? Maybe we can help you find an alternative method.
But if it must be all on one map, we can bake the entire environment onto one giant 4096x4096 texture (maybe smaller is possible).
Anyways, let us know!