poke I tried to use the Broceliande script but not work for me.
But I had progress using your instructions and part of Broceliande procedure for Batocera 5.22.
This is the steps may can help others (for Dell Vostro 5470 gpu-hybrid Gt740M):
1) mount -o remount,rw /boot
nano /boot/batocera-boot.conf
<remove the leading # from the nvidia-driver=true line>
2) create 99-nvidia.conf in /etc/X11/xorg.conf.d/
<Add the following lines inside>
Section "Module"
Load "modesetting"
EndSection
Section "Device"
Identifier "nvidia"
Driver "nvidia"
BusID "9:0:0"
Option "AllowEmptyInitialConfiguration"
EndSection
3) Edit xinitrc in /etc/X11/xinit/
<Add the following lines inside the customisation block>
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto
4) Saving the changes
cd /recalbox/scripts/
./recalbox-save-overlay.sh
Reboot
After restart the switch for Nvidia driver is permanent.