So far I know I should use
options nvidia_drm modeset=1 fbdev=1
Files in /etc/modprode.d/ are read in numerical-alphabetical order
To read the modeset .conf file after mhwd-gpu.conf
sudo tee /etc/modprobe.d/nvidia-modeset.conf <<< 'options nvidia_drm modeset=1 fbdev=1'
If that does not work, change the name to drm-modeset.conf so it is read before mhwd-gpu.conf