TBH, there is no need to download the entire package of root certs from a new
version of macOS. Installing the updated root certificate you need should be
enough. For the case of the expired intermediate certificate of Letsencrypt
(that causes most of the problems in my personal experience)
You can use the command-line SMCFanControl app (it’s in the app bundle) to
lower the fan speed (you can’t do that with the standard UI).
I know because I used it when I damaged some sensor changed the HD to an SSD in
a Mac mini and the fan were always at full speed, so I built a python script
