I just entered the modern era in my game. Immortal in this appears to be approaching base game's Deity level as far as science goes in the mid Industrial.
It looks like "-8" is the current Immortal level while "-6" was the previous Immortal level beta version, maybe "-7" would be closest to base game's Immortal level?
I suspect this means that Deity should be at "-10" (also half way between the current & previous versions)
On other changes, if it's not too difficult I'd have the AI only place spies on the players they don't like instead of their friends. Humans really get mad when a friendly AI steals their techs.
continuation of above game:
170: Carthage build Forbidden Palace
Rome proposes Banning Cotton. I'm getting that thru my city state ally. I'm not seeing any other sources, but with so much of the world not explored yet ...
171: Spain wants to be friends. OK
173: Great Prophet born -> Holy Shrine
174: America completes Globe Theater.

No, I wasn't building it at the time, I'm actually in the middle of building Leaning Tower, but had intended to choose Globe Theater as my free wonder.
Spain steals Printing Press.

We have an active friendship
175: America completes H Castle
177: I complete Leaning Tower -> GE
178: I meet a city state, no more left
180: Carthage wants to be friends. OK
181: I complete Sistine (via the above free GE)
I discover Lake Victoria. 1 left
185: I open Rationalism, not wanting to triger a GA only 100 points away from one nor wanting the free Great Artist yet
188:
Carthage declares war on Incas.
189: GS born -> academy next turn
190: America & Greece enter Industrial era
191: I discover Grand Mesa, no more natural wonders left.
192: RA completes
193: Carthage enters Industrial Era
I enter Industrial Era via Industrialization (I chose this to avoid having another Great Prophet born which would have if I waited until Sci Theory)
Beginning of Industrial Era status
Me: 36 techs. #1 pop, crops. Last science
Rome: 38 techs. Rean
Ott: 39 techs. Rean. Last is most categories. At war with Carthage. Friends with me & America
Incas: 39 techs. Rean era. At war with America & Carthage
America: 40 techs. Industrial era. #1 man goods, land, science. At war Incas. Friends with me, Ott, and Carthage
Carthage: 39 techs. Industrial era. #1 troops, approval. At war with Ott & Incas. Friends with me & America
Greece: 39 techs. Industrial era. #1 GNP
Spain: 39 techs. Rean era. Last in approval. Friends with me.
194: Rome enters Industrial era.
World Congress welcome city states.
While I could deny Carthage the chair, it would make them a lock to propose resolutions so I vote for myself.
195: America completes Taj Mahal
RA completes
As expected, Carthage became host.
196: Spain enters Industrial era
I use first faith based GE to rush Uffizini. (Lots of AIs have at least 1 sub policy into it while none have sub policy into Rationalism)
197: Carthage completes Red Fort
200: Incas enter Industrial era
Carthage captures city from Inca. It's on Incas starting landmass.
I add Flourishing of the Arts, extending a GA that just started by 10 more turns.
201: I vote for Arts Funding
202: Ottomans enter Industrial era
Arts funding passed 10 - 2
Banning Cotton fails 8 - 7
203: Carthage proposes embargo of Incas
Greece proposes banning Cotton
205: I complete PT. Free GS - > Academy
206: RA completes.
207: Carthage enters Modern era. Carthage adopts Autocracy
208:
Carthage captures Inca's capital. Incas have two cities left, but this kills the luxury deal.
210: I add Artistic Genus (to fill Ufizini)
211:
Spain declares war on Ottomans.
RA completes
212: Greece enters modern era. Greece adopts Order
215: America adopts order
216: Rome denouces me.
Ottomans enter modern era.
World Congress expands infrastructure
I actually don't want anyone that could get it since they've all adopted an ideology that I won't be. I vote for myself
I denounce Rome
217: Ottomans adopt Freedom
Carthage remains host.
218:
Carthage & Incas sign peace treaty.
I complete Oxford and choose Radio to advance to modern era.
Beginning of modern era status
Me: 46 techs. Last in science.
Rome: 49 techs. Industrial era
Ottomans: 48 techs. Worst in troops. At war with Carthage & Spain. Freedom Civil Resistance wanting Order. Overall -2. Modern era
Incas: 47 techs. #1 approval. Worst in population, crops, man goods, and GNP. At war with America. Industrial era
America: 51 techs. #1 pop, crops, GNP, land, science. Worst happiness. At war with Incas. Content with their Order, but their overall happiness is -5. Modern era.
Carthage: 50 techs. #1 man goods & troops. At war with Ottomans. Autocracy, but has dissents wanting Order. Overall happiness +4. Modern era
Greece: 51 techs. Content with their Order. +12 global happiness. Modern era
Spain: 49 techs. At war with Ottomans. Industrial era
I'm in best position for a cultural victory, biggest threat is that there is a chance someone could launch the spaceship.
Attached are screenshots of beginning of Industrial & Modern eras.