I see; I also prefer the option of fixing broken features; I hope we're able to.

Anyway, back on balancing, from what I can see from more testing, Medieval and Renaissance are still far too quick. So if we don't want to increase tech costs for those eras, we need to tune down everything else I suppose. At least I don't see a great imbalance between Monarchy and Republic now.
Here's how techs are distributed by era
38 ancient
30 classical
29 medieval
37 reinassance
60 industrial
56 modern
58 transhuman
I suppose the best idea would be to have eras lasting the same number of turns, maybe eras from industrial onward should have some more turns.
My idea for balancing the game would be:
1. testing with some standard settings, possibly on blitz speed to make a rough balancing faster. I would do that with multiple starting savegames and help from other forum users, autoplaying the game until the last turn and posting saves every 60 turns so that we can collect data faster and we don't apply changes based on just a single test. I know it can be boring looking at the game autoplay, but it's the fastest way.
2. roughly balancing other eras by just multiplying values in gamespeedinfo by appropriate factor (it worked in the past, so I don't think it will be different now)
3. some more fine tuning starting from different saves, this time without autoplay, just some real game if people are willing to help.
4. testing with different mapsizes & balancing mapsizes
5. testing with different handicap levels & balancing difficulty levels
6. testing different options which can severely impact the game (for example with/without revolutions, with/without tech diffusion, with/without barb civs, ecc).
I think this is the best and the fastest way to properly balance the game.
Opinions?