Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
One way to resolve this would be to script the custom installer to make it work like the pre-2016 installer did. Any WSH experts on here? I don't necessarily want to learn how to use WSH just for this, but if someone's got plenty of experience with it it'd be a case of downloading and unpacking the custom installer as per BradM's post, throwing up a dialog allowing users to check what they want to install, creating an XML file based on the options, and launching the installer. I could do that in Python, but that doesn't come preinstalled with Windows...
As a former co-worker of mine used to say, "If they can't get their s**t together, maybe we can get it together for them".