Setup that allows immersing oneself more in an era?

Is there a particular setup that allows for maximum immersing in a particular era? For example, I want to play and achieve a lot of things in the classical era without having a lot of stuff obsolete quickly.

Slower game speed is a possible option, but according to this thread production and everything else becomes slower as well, so the difference is probably just units can move relatively quickly, and players can't respond to wars, units getting killed or other new situations quickly. But probably this doesn't allow for a lot of interesting things going on within the same era, it just means more clicking on "next turn" and more waiting..

Another option is by playing scenarios. For example, the "Into the Renaissance" scenario does allow you to immerse in the gameplay of the medieval era without slowing down production, etc. But there is a limited number of scenario and it's not easy to make your own.

So, wondering if you guys have any particular game setup or tricks that works better than the above options.

Extended eras mod*. Marathon speed science, standard speed construction.

May actually be called something like historical eras. The speed it sets it to is called "historic"