Hi and thanks for this link I've searched on forum but I didn't have found this, but it isn't a structure problem, but a problem related to making the surfaces seamless with a smooth transition, the structure I understood how to make as you can see but it is a problem on continuity without noticeable edges like the picture attached below and like what it's made with NX or CATIA.
and also with Blender I get a good result from how you can see from the image

Surface smooth exported as Step file with Moi3D from the subdivision surfaces


Moi3D Gyroid with blended G3 tangent spline structure but is still visible the seam on between them