I second that as well, this mod unfortunately cripples/nerfs AI more often than not from my experience. I think it would be nice to have it be a "human player only" feature.

i second that. Only for players would make it "fair" on the AI

I like this mod for OCC playstyle, but I noticed that if the mod is enabled, the AI doesn't expand as much or they do expand but their civilization suffers because the mod is interfering with the default bonuses. Is there any way to limit the mod for PLAYER ONLY?

Yes. The advantage of that is you get to stack the extra Housing and Amenities on it. Downside is all your other cities are scuppered.

Can you build all the Switch To Tall projects in one City?

No idea.

Is it compatibke with JNR's districts?

Thank you, that makes the game even more balanced!
Here some naming proposals for special tech switch projects:
Scientific: Mass Higher Education (I), Elite Scientists Training Program (II)
Cultural: State Humanitarian Grants (I), Modernized National Broadcasting (II)
Economic: Centralized State Taxation (I), National Monetary Control (II)
Theological: Highest Priests Council (I), National Theological Education (II)

So Mayan settlement type game

Say for example your buildigns give +x% to a resource, but only in the city it's built. Or only in the cities that are within...3 or 6 tiles of it. Or that the bonus deminishes for every city that you have until it's zero. THAT would encourage a tall build. Cause you'd want to get those cities that are within range, or the few cities you can affort without loosing the bonus, as big as possible. Kinda like Maya civ are doing it.
What numbers to use? I dont know. It's hard to balance. But it would have to be something where you pay the same amount of production (or less to encourage it more) to build the building and focus production on those core cities, as it would cost you production to build more cities with more districts.

I'm sorry. While I find this a great idea, I dont think your 1 per empire building bonuses are that good.
They just discourage building any buildings that these buildigns here nerf.
And if a player plans to build more then 2-4 buildings of the ones that would get nerfed by your 1 per civ buildings, that player just doesnt build those 1 per civ buildings at all. And most of the time, they will come out with more yields.

What I'd suggest is that, instead of punishing people for building more, you encourage to focuse more on core cities.
Civ 5 solved that by giving percentage increases for core cities, which you loose if you have to many cities, thus encouraging feeding those cities with food, production, trade routes, etc.

Interesting idea. But it doesnt realy discourage going wide or encourages you going tall.
Building one of these buildings on average gives the same as 2-4 of the buildings they make worse. Plus a little extra, that's not That worth it most of the time.
So you basically remove part of the yields of 2-4 buildings you've built already, and move them to another building, that you can only build once. So all you do is pay more production for what you already had (again plus a small bonus, like a housing or an amenity here or there).
The only time those buildigns are worth it, is if you can only build one district with the buildings that these buildings would nerf.
Otherwise it's never worth it.
And most of the time, you want more then just 2-4 of those districts/buildings in your empire. Especially if you're focusing down a victory of a specific type, like culture or science, that realy depends on you having a lot of those buildings.

I've noticed that they usually build 2-3 of them.

Does AI know how to use these buildings? Or is it going to build them every time no matter what?