For the ESR release, you can use Group policy (Windows only) or policies.json (all systems) to make it accept the system cert store.
For all releases, you can make the process of joining the domain to also include installing the cert into Firefox's store. For example, the Redhat's ipa-client-install does install the certificate into the Firefox store by default.
For all releases, you can make the process of joining the domain to also include installing the cert into Firefox's store. For example, the Redhat's ipa-client-install does install the certificate into the Firefox store by default.