In the stress test version of the game when you placed down a building it would add a foundation texture in the terrain below the structure.
The issue is that this foundation can be seen through the fog of war without having to scout the area again which can make hiding buildings impossible.
The information in the fog of war can reduce the burden on players. It’s like the scout recorded what was in the position at the time and wrote it on paper.
I’ve made threads about fog of war issues both in closed beta and stress test, hope it gets fixed before launch, as it can actually decide games depending on the kind of information (and timing) you get from it.