In UE version 4.24.0, there’s a built-in plugin called “Datasmith glTF Importer”. (Not to be confused with the other “glTF Importer” that’s in Beta and developed by Khronos directly, which was broken last time I checked.) You can now export a .glTF file from Blender and import to UE using the familiar Datasmith interface. It seems to support the Principled BDSF shader as well in the limited testing I’ve done so far. Not sure how far it goes beyond supporting the metalness & roughness values.
I was able to export a complex model from Revit to Blender using FBX and bring this into UE via glTF/Datasmith without issue and generate lightmaps.