The answer so far I have found that works is to set Blender unit scene to 0.01, then scale the bones until is big enough like, 10 or 20, then apply the transforms with Ctrl + A > All Transforms (or at least the scale) and it works, but it seems unnecessary, even the pipeline Send2Unreal tells you that setting it to 0.01 is not a good idea.
Any other solution?