the question is directed to Jeremie, but i wanted to tell you my experience regarding Zbrush;SP,3DStudiomax.
Fbx exported from zbrush never ever gave me probles,when the scale (zbrush "export" settings) is the same as the low poly.
But 3DStudio Max can give you some troubles.
If you modifiy your UVs in 3D Studio and export a fbx for Substance then you MUST check
automatic Unit conversion in the fbx export dialog/3dsmax.If you choose any other measurement you basicvally get black bakes in SP
