Added button “Export Selected To Editor” that only exports to UE4 but places nothing in the level. Good to update existing meshes or in cases where the mesh has been made into a Blueprint. Also fixed the pivot so it no longer centers on export.
Made a pull request. Until it’s updated you can get it from my fork at
https://bitbucket.org/Gigantoad/m2u/branch/develop
Of course it’s probably **** and may not adhere to concepts of 
But it seems to work for now.