that is a bitter thing i try to prevent. time scale between turns massively reduces over the ages to reflect that everything is becoming faster. while at the game start decades of years pass between two turns it's down to months in the 19th century. so no need to boost the game speed additionally. i want to keep it somewhat constant - so a snail game feels like snail in every age, even in the transhuman and research takes more then one turn!
i've put the population requirement up to 25 and set the tech requirement to social contract (although realistically it far too early for mega cities to occur) but therefore i added a national wonder like building with the same function that can be build in the capital earlier with easier requirement.
i suppose it won't work balanced... i've increased the additional maintenance to +50% but i fear even that won't help much.
IMHO, your logic here is slightly flawed. I understand why you'd want a snail game to feel like a snail game all the way through -- but as you pointed out, your games are usually long over before you get to the modern age. So if you're going to be balancing the game for things like the modern era, please, please, please play on a faster speed so you get there and can actually see what's going on. Otherwise you're trying to balance the rest of us on a speed your not playing, in an age you don't get to, for concerns you're not seeing first-hand.
I like the increase in game speed. Even if the turn is now a year, if I have a large city, factories, etc., I should be able to produce mech infantries in 1 turn. This has been a core design element in every version of Civilization I've ever played, and I don't think you're going to fix it with just buildings.
Let me give you an example why this will be a problem:
Lets say turn intervals are 1 year. A war breaks out. The enemy sends their mech. infantry into my territory. Base movement cost is 2, plus their using my roads with a promotion, so they can move 5-6 spaces in 1 turn (which makes sense that an advanced unit can move that quick). If, because you want things to feel on "snail" speed, you've changed production so that it takes me 2-3 turns to build a mech. infantry, the game is badly imbalanced. Why would it take 2-3 years to build a single unit, but enemy troops can move 6 squares in a year? Logically, it just doesn't make sense, and worse, it creates a frustrating game.
So that's what I mean about balancing the end game -- you have to look at everything (movement costs being a big one) to make things scale consistently.
If you really want things to feel snail the whole way, I would recommend the following:
- Create a new modmodmod that is different than the building upgrades (e.g., "Consistent Speed Mod"
- There should be significantly less increases to movement speed over time (a warrior moves 1 space every 20 years, the time interval changes to 5 years, they should only get 1/4 movement; so a new unit with 2 movement points should only get to move 1/2 a space, and so on)
- Dramatically increase all research costs to scale with the changes in the game interval (so if I could research Drama in 1 turn at 20 year interval, then it should take me 4 turns if it's later in the game and the interval is now 5 years)
- Change scaling of hammers / food / culture / commerce /etc. so that if 1 turn is 20 years and it produced 20 hammers, then if nothing changes, and the interval is now 5 years, they only produce 4 hammers (I'm sure you get my drift).
The benefits then, of building upgrades, farms, etc., isn't to "increase production capability" as much as it is to keep up with the game's scaling.
This would be a major undertaking (obviously). But please, please, please don't try to fix this issue with building upgrades. Just my $0.02, thx!
But as you can see in the pic's the religion is there.
. I'm posting this more as curious person than anything else 
. Personally, I think the mod without these codes in or with them will make no difference because what you have now is a tremendous mod of a great mod!
I'm very pleased with the modmod and highly impressed with all the amazing improvements...it really is a whole new game compared to vanilla BTS!
