First off, there’s a line of code in Blender that you need to comment out (I recommend using a second install), that fixes any root bone issues. I’ll try and find the documentation and post a link. Second if you export the UE4 character (from UE4) as an fbx and use that as your template (just open it in Blender without touching it at all) then export it at 100% scaling … in theory that should work. That’s how I do it and I’ve never had an issue with any of the stuff you guys seem to be fighting with.