I wonder if the dynamic Mesh technique from the DemoRoom, which can be edited in several ways, like lenght of the rooms, height, mirroring, etc… can be used for designing the whole map with a few clicks. But how does the engine respond to that? With all the lighting and physics will they be handled like normal hand placed static meshes?
I dont know the demo room off hand but yes it will take at least some performance, the least of which if you set up LODs and such but using blueprints to setup lengths etc. using multiples of meshes is the same as placing x number of meshes and they will handle everything as if they were. Instanced static meshes are the exception but they arnt used in the demo room to the best of my knowledge, a newer feature.