[ADDON ] UE Tools

I’m trying to export some animations but the epic ik_ bones always get exported in the wrong position:

What can I do to get these bones exported correctly?
I have tried adding "Child Of’ and “Copy Transform” constraints to their corresponding bones in the hands but, although they follow correctly their parent in , the constraints seem to be lost when exporting.

I’m using 2.78a and UETools 1.2.4