Had same problem and could not find an answer on the web so here is a work-a-round (i use blender)
before exporting your object, add a simple (tiny) polygon under your current object, equal to the high of your current object (no now the object is twice as high) so that the center of the object becomes the base of the main object (so it kinda like setting the object centre buy using its total size)
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/ a box /
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// (addition of tiny poly as base of final object)
