How to make xinit / startx to read my custom xorg.conf.d files?

[Me]

I am running Arch Linux with the i3 window manager.  Today I switched from 
lightdm to xorg-xinit.  I have read the available documentation, and 
configured things so that startx will start and run the X server, and i3wm 
runs fine after that.  However, I have one very important problem that I 
cannot find an answer to.

I have a Nvidia GPU with proprietary drivers installed, and I have created 
a file named 10-nvidia-drm-outputclass.conf in the 
/usr/share/X11/xorg.conf.d/ directory.  The contents of that conf file are 
as follows:


Section "OutputClass"
     Identifier "nvidia"
     MatchDriver "nvidia-drm"
     Driver "nvidia"
     Option "AllowEmptyInitialConfiguration"
     Option "Coolbits" "28"
     ModulePath "/usr/lib/nvidia/xorg"
     ModulePath "/usr/lib/xorg/modules"
EndSection



An important line in that file is the Option "Coolbits" "28" line, as it 
allows me to set a custom fan speed for my GPU, which I need for these 
warmer months.


When I use startx that conf file is not being read, it seems.  It is 
completely ignored, and I am unable to set a custom fan speed.

Is there a conf file for xinit that I can use, create, or configure that 
will access the 10-nvidia-drm-outputclass.conf file, so that the GPU will 
run cooler via a custom fan speed?

When using lightdm, it works like a charm.  But as I say, xinit seems to 
not see/read/access that file.

Any help would be greatly appreciated!!

C.M.Millington
-- 
Thank you!