I’d be really interested in having a pre-construction script for blueprints - something you could use to spawn static meshes and lights and other objects with their mobility set to static programmatically for precise and quick design and have those things used to build lighting and such (or even just getting the ability to spawn static mobility components within the construction script). The engine seems to handle things like this really well in terms of rendering a bunch of instanced static meshes without poor FPS (each beam is a separate instance):
but when it comes to actually making something like it’s a real PitA that could be done a blueprint small enough to fit on screen without scrolling if there were a way to create instances of instanced static meshes with their mobility set to static (without mobility set to static it starts to slow down significantly so there’s no way to make this stuff programmatically for stuff that will never be moving in-game that I’m aware of without suffering a severe performance hit).