Streaming optimization (UE4-26)

hello all!
I’ve a specific question regarding streaming optimization. the thing is, I have a large number of actors in my scene which I should reduce to improve performance. I’ve already looked into HISMs, reduced material count on meshes as much as possible, utilized LODs, reduced shader complexity etc…
the FPS I get in the scene is good, draw calls are within budget, but when I approach this location that is dense with actors I get stuttering while loading which suggests the issue with streaming.
what I’m looking into right now is reducing actor count without deleting actors which would make the scene look like cr*p. so, the options are:

1.) merge smaller “clumps” of meshes and materials by creating atlases
2.) merge larger “clumps” of meshes but not merge materials, use atlases on LOD1-3, but not LOD0

the issues:

  • with the first option I’ll end up with slightly reduced actor count because I can’t merge many (or large) meshes because I’ll lose texture resolution up close, but I’ll reduce a lot of materials and lower draw call count
  • with the second option I’ll greatly reduce actor count since I’m not merging materials on LOD0 thus I can afford to have more meshes merged, but it still leaves me with a ton of materials on LOD0 and a lot of draw calls, plus additional atlas textures for lower LODs

finally, the question:
both of these methods will help in the end, at least so much, regarding performance. before I spend a few days creating both scenarios to test it out myself, I wanted to ask if anyone has experience with this particular approach and, by your opinion, what would be prefered method regarding performance? by that I mean which method would reduce streaming cost the most?

thank you! cheers!
Denis