Hey, you know if you utilized punctuation and new lines once in a while I’d actually try to read the whole thing…
Aside from that and all the bla bla bla, have you ever considered just loading in what you need yourself?
Put placeholder single tris meshes with a collision hull down using the foliage tool.
Add a cylinder around the player that is set to not be visible in game, on a specific collision channel that only responds to the instances you placed, and obviously make sure you have overlaps and sweep on.
With that, just get a collection of the instances that are overlapped, and swap them out to the right mesh models while retaining the original random transforms used by the foliage system.
Very Similar to this - DynoFoliage: UE4 Interactive Foliage
The difference being I was swapping foliage with animated skeletal meshes.
Even with Billions of instances, the load cost of a single tris should make things bearable.
I still don’t understand why you bother at all with trying to use a bad engine and an even worse system.
If you just go back to world composition you would have no issues at all.
And in theory, you can also parse through and swap Grass meshes, but you need to create classes in C++ to read the collection data, so its a lot more involved that just using BP.