the reason for more than one elif is for different package managers like apt, yum and dnf, other than that it just skips it if the package is detected.
Afaik it uses cli to find the temperature. i couldnt set the temperature with nvidia-smi so i had to use nvidia-settings
Yes the loop is nice, but you know your packagemanager and that this package will not disappear randomly, so keep it out of this service script, its just an extra break point and wastes resources :D