Sorry, I forgot to answer your previous question and mention that the scale is performed when exporting.
File->Export->FBX : Scale : 100 (export parameter on the left of the window)
I will need to think about using world setting to handle the x100 scale and always export as 1.0 scaled. It could be an option.
Edited: using world settings for me is not working and Unreal complains about different bone transformations than the original.