We started working on this problem a year ago: share surface materials between Blender and UE4. Use Cycles/Eevee materials directly in Unreal, with a fully editable procedural node network on both ends. And got much of it working!
After interviewing game artists at GDC, ECGC, and SIGGRAPH, we shifted focus to develop kick-■■■ StaticMesh import/export. Something people wanted right away.
Should we dust off the Brigge for Materials prototype since there seems to be interest?