Era Advancement Mode based on set Turns

So If we look at the 2 best games which are on top, Civ 6 and Humankind. They both have this Issue where the early/mid game is so much fun, The later stages are a drag. Technologies and turns don't mix well.

So we introduce a game mode where Era advancement happens only after a certain set of turns are reached and the player gets to decide how many. However the start system is the same and you can pick which civ you want to advance to as usual, but the actually advancement will happen only when the turn amount is reached, 

So If I want the First era to last 50 turns before the next one and the next one to last 100 turns I can do that. 

I can fight wars , use all my units . my researched tech is not a waste. My Greek hoplites can actually fight in wars. This paired with the custom difficulty I talked about inanother topic, Wil enable palyers to have a toattly diffrent experience playing humankind.

In terms of game enjoyment the more ways you can paly the same game the better it is for us palyers. and the ability to Customize everthing is key.