Do servers and PCs outside Intune trust these certificates?

Devices managed by Intune already do. The certificates chain to the client's Passbeam root, which Intune's trusted certificate profile installs.

Anything else needs that root added once. Download it in Passbeam from Authorities, the top row.

One Windows server: in PowerShell as Administrator, run Import-Certificate -FilePath .\riverside-academy-root.cer -CertStoreLocation Cert:\LocalMachine\Root with your file's name.

Lots of Windows machines: use Group Policy. In Computer Configuration go to Policies, Windows Settings, Security Settings, Public Key Policies, then Trusted Root Certification Authorities, and import it there.

Linux:

# Debian and Ubuntu$ sudo cp riverside-academy-root.cer /usr/local/share/ca-certificates/riverside-academy-root.crt$ sudo update-ca-certificates # Red Hat, Rocky and Alma$ sudo cp riverside-academy-root.cer /etc/pki/ca-trust/source/anchors/$ sudo update-ca-trust

Java apps, Firefox and some appliances keep their own list of roots and need it adding there as well.