I noticed that this https://forums.unrealengine.com/unre…e-4-20-preview seem to indicate that the following bug reports are scheduled for 4.20. If that’s true, then it’s good news:
UMaterialBillboardComponent Memory Leak and Hitching (Unreal 4.19.2 + 4.19.1) Unreal Engine Issues and Bug Tracker (UE-58673)
Extreme hitching when using profile command (stat startfile) + other stat commands Unreal Engine Issues and Bug Tracker (UE-57976)
Particle Mesh Emitters Cause Heavy FPS Stutter Unreal Engine Issues and Bug Tracker (UE-58676)