Hi @SJLPHI , how are you?
Really? Gosh, I took my conclusions from your posts over there:
Those two were decisive for me and made me conclude that without major changes to the recipe it would not work. In the end, from the user PoV, optirun is simpler than __NV_PRIME_RENDER_OFFLOAD=1 __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G0 __GLX_VENDOR_LIBRARY_NAME=nvidia…
@malcolmlewis, first of all sorry for the time to answer you back this time. The idea of using the hard way worked in the end. The drawback still was that as I can’t deactivate secure boot on the bios, the installer complained about the unsigned driver and refused to install.
Unfortunately, I did not find an option for the cuda installer create a pair of keys to me, so I ended up having to accept to disable mokutil. It worked afterwards, but at the ugly price of having the boot informing twice about having an insecure system at boot time. 
How can I get rid of that message? How could I have generated the pair keys in a simple way?
Thank you for all help!
Best regards