There is a good reason not to make gates/lanes house-specific if it increases amount of design work beyond the reasonable level: all of them are built by Liberty's Ageira/DSE with minimal involvement of other Houses corporations, so 'by default', economically standardization makes sense.
From the construction standpoint, the gates and lanes are built as frameworks, in which the actual parts that generate spatial effect (aka Whiteboxes) are integrated. That being said, I think that Ageira would have fulfilled requests for special design of gates and lanes frameworks for certain House systems (like capitol systems or the sovereign space). It won't actually impact their functions as long as the Whitebox parts could be installed in the same positions.
So cosmetic changes to how the model looks like are totally acceptable, from my POV. Moreover, they might help players identify that they are entering rule-wise special (i.e. captiol/sovereign) systems within the house space.
