Flabbergast is solving a different but related problem, it's about expressing the state of your system. Lots of times you want to say the dev environment is like the prod environment, except for these 3 things. And by the way, anything in the European region needs different settings too that interact with dev/prod.

I'm a fan of Ansible, but it isn't really suitable for expressing multi-dimensional and multiple-levels of exceptions, from experience it works for about 2.

How that state is actually rolled out is the job of something else (which could be Ansible or the update portion of your cluster scheduler).