Foliage tool is freezing engine?

Back in 4.13 and 4.12 I could place large volumes of Spreedtree created grass with some slight lag, but recently and after the 4.14 update the foliage paint tool freezes for like 10 seconds or more when I try to place any grass or alter the landscape around it using the terrain shaping tools. Sometimes when shaping the terrain under it it even will indefinitely freeze and then begin to cap out my 20GB of ram, rendering my PC extremely slow and barely working until I force close out UE4. I initially thought it was the specific grass mesh, but after further testing of a different one it began to have the SAME issue after only 20,000 or so instances. It is heavily hurting my ability to perform level design.

The scene has over a million placed instances of said grass mesh (and thousands of other things such as trees, bushes, etc). They all have LODs and culling on.

PC specs are 20GB DDR3 Ram, AMD 8350 CPU, 990fx Killer Mobo, and a MSI GTX 980 TI GPU.

don’t know if this is related or if it helps: i’m trying to merge 2 branches of unreal and at this point I also experience a crash related to a memory leak, while loading the foliageedit.dll. maybe it’s related…