@Benjy, did you find any workaround on the issue of orientation when exporting FBX from RC to Zbrush?
I still don’t understand, why does an obj mesh works fine but not fbx??? FBX is much more common to use in the industry than obj format and add the fact that fbx gives you as 300% less of file size than obj!
My current workaround is to open the fbx file in blender and “apply” the rotation values in there, export to fbx (again) before I can finally use the mesh on Zbrush.