I see your situation now.
> I attempted unsuccessfully to install 2.4.3 community version locally and on CentOS 7.x using yum.
That's strange, we've done several installs on CentOS7 lately, and they went ok. Do you remember what was the problem?
>The https://github.com/GluuFederation/install instructions have been deprecated and the link to new does not work. I did not wish to break the 2.4.2 install. For that reason, I stuck with 2.4.2.
I believe, this is the correct current link to CentOS7 install guide: [https://gluu.org/docs/deployment/centos7/](https://gluu.org/docs/deployment/centos7/). This is our official docs portal, by the way, and it has some guides on configuring OIDC, as well as gplus script, too, so feel free to have a look at them.
I understand your worries about breaking your current setup, but may be we still could go with a clean install of a separate 2.4.3 instance (on another vm) and migration of all settings to it from your live 2.4.2 instance? Do you think it's still possible at this phase of the project?