Not sure: Built buildings you get the right to have a free one from conquest- as is, or auto-sell and instantiate the free one immediately? Victim civ cities lose their free Broadcast Towers when the civ loses C
I am not sure if it is directly related to this issue, because it does not involve an additive pipe, but I think only the devs can say if the additive pipe or the linear pattern is the root cause. It is definitely another example of "shapes created by linear pattern" are not correct...