I still do block out with BSP. Yet I’m from the UE 2.0 gen… mapping in UT99/2k3/2k4. I’ve got a solid grasp of the geometry tools, although lacking from what they use to be.
For most of my block out I use simple primitive meshes. Cube, Cylinder, Plane, Sphere. I scale them as needed. If I need a bit more complexity I’ll jump to BSP.
Ramps, rooves… anything triangular = Cone BSP. More complex (concave/convex) = pen tool
With BSP you don’t have to add collisions. This speeds up the process a bit, but you will take a perf hit with the per poly collision. You also don’t need to deal with UV mapping on simple stuff.
None of my block out/white boxing is ever super detailed. I do it for scaling, spacing, flow and grouping purposes. More of a 3D doodle so to speak.
I will do BSP door, window, archways, stairs, stair to upper floor entry etc. But they are very simple and done for character movement testing.