Which of these renderer settings mostly cause huge VRAM consuming?

I have set mesh and texture streaming to true, but this did’t help. I have also set simple scene as editor startup, and the editor has opened, but crashed after switching to the main scene. I have solved this in non-trivial way:

  1. Load the project with the “dumb” configuration, without Lumen, Nanite, raytracing and so on, with DX11 and SM5.
  2. Export landscape heightmap and all paintings.
  3. Create new “Empty Open World” level.
  4. Create MULTIPLE landscapes if you have world more than 8x8 km. One landscape = 8x8 km.
  5. Split heightmap and paintings received on step 2 into pieces mathing with landscapes created on step 4.
  6. Import all these pieces into new landscapes in the appropriate order.
  7. Copy all actors from the old level into the new one.
  8. Ensure that you haven’t forgotten to set all level-specific settings you had in the old level such as World Partition grid cell size.
  9. Now the most important step! Open world partition editor and UNLOAD as much landscapes as you can (preferably them all). (In my game I have two landscapes, one of them contains water so I cannot unload it (this is an engine bug) but the second landscape of size 8x4 km (1/3 of the whole game world) is being unloaded successfully so the VRAM consumption had reduced by almost 1.5 times.)
  10. Close the editor mandatorily in the “correct” way (not with terminating the process in the task manager), switch back to the normal rendering configuration (I have a .bat script that does this), load the project and do NOT load the unloaded in the step 9 landscapes in the normal configuration, place new actors only in “dumb” configuration.
    Who knows is this way “correct”, does it not have hidden side effects?