For you guys working with Armature:
If you set blender world scale to 1.0/metric and also set export scale to 1.0, the armature scale wont get messed up.
In UE4 set the import scale to 100.
You may get an error during import stating that physics asset can not be generated because bones are to small.
On the import mesh -> create -> physics asset -> set min bone size to 0.05 -> works fine
Ive been setting up blendspaces and so far i did not run in any further trouble, but i took me a whole weekend to figure out the blender exporter scaling mess on armature. I hope they will fix this soon.