Steam VR hitch with 3d UMG Widgets

After ~30 minutes, a scene with 3D UMG widgets will hiccup, briefly showing the steamVR background

Attached Example project from User VRDropedFrame (4.19) + Example project I created AJ_VRWidgetPerf (4.18)

prerequisite: Acquire Vive or Vive Pro
1. Add 3D Widget components to pawn or scene
2. Play in Viewport Preview or Packaged project
3. Let it run for ~30min+

Result: Steam compositor will hiccup every 10 to 30 seconds (Lighthouses momentarily visible for a split second)