For a single mesh, I rotate -90 in X, apply transform, then rotate 90 to export as FBX scale, it is easy.
But when it comes to multiple meshes, I have to repeat the process above, one by one, or it will carry transform data, which is really tedious.
Moreover, for the skin-mesh, the bone hierachy exported from blender always carry some extra data. Say, the transform data from parents will add to child bone, or child Empty,