Some suggestions I would like to see in the future.
More dynamic name changes expanded
I feel like some civs are still lacking a bit of variety in terms of name changing during specific eras in history. Some examples are the Mali, Morroco, Khmer, Babylonia, Greece and Ethiopia
For Mali during the medieval/renaissance era once the capital goes to Gao the name will be changed to the Songhai Empire even if the empire was short-lived it's just a nice little touch
During the renaissance and beyond West Africa was pretty much fractured and disunited but some empires still flourished during this period like the Kaabu Empire. For modern names it can be called the Mali of course but also Ghana, Niger, Mauritania, Senegal etc.
Morroco itself has already decent name changes as a civ but it can be expanded upon
Medieval era: The Almoravid as an empire and the Almohads when the civ runs theocracy.
Renaissance era: Kingdom of Morocco is fine but once they are an empire it changes to the Saadi empire or the Alaouite empire (even if the last one isn't even historical at all) When it runs as a city state it can be called as the Barbary States or Barbary Coast which during the 16th and 19th century where huge pirate activities around the Maghreb and the Mediterranean Sea.
For Khmer the only major one missing is the modern kingdom of Cambodia if it ever respawns in the modern era.
For Babylonia I rather see it start as the Sumerians and once it's capital change to Babylon it's the Babylonian Empire. For modern respawn the Republic of Iraq.
I rather have Greece in the ancient/bronze age refer to as the Mycenaeans/Mycenaean city states or kingdom
There are probably more to mention but right now this stands out to me.
More ancient civs respawn/reborn into modern nation states
This pretty much coincide with the first suggestion about having more dynamic names for each civ. This time when they respawn into the modern era. This also means that more ancient civs can respawn when nationalism is discovered.
I already made an example about Mali, Babylon and Khmer.
Other civs are:
The Phoenician/Carthaginians
When the capital is Tunis they respawn as Tunisia, when capital Algiers as Algeria, when capital Beirut as Lebanon and maybe as an extra when the capital is Jerusalem with Judaism as a state religion as Israel
Harappa
This one is tricky but I was thinking for the Harappa's to reborn as the modern Bangladesh or Burma/Myanmar. They can also appear during the renaissance era as the Sikh Empire however that empire was very short-lived and it will also mean that Sikhism has to be implemented in the game as a religion. Unless you like to play ahistorical and make Sikhism the dominant faith on earth that is.
Ethiopia
If the capital is in Mogadishu and it has Islam as a religion it will be modern Somalia
Polynesians
This might be controversial and tricksty like the Harappa one but I can see them reborn as modern Australia or New Zealand since the Aboriginals and the Maori's where of Polynesians descent afterall. Right now Australia feels most of the time empty and there core can move to Australia or New Zealand. Maybe if it runs as fascist it can be called als the Neo Tonga empire or Oceania Empire
More modern leaderheads
This also goes in line with the second suggestion. Modern states means also modern leaders however this means some leaders need to be made animated and researched about them.
Few examples:
For the Dutch as modern leaderhead:
Queen Beatrix or Queen Wilhelmina
For the Russians:
Michail Gorbatsjov or Vladimir Putin
For the Spanish:
We already have Franco but if Spain decides to be a democracy then Adolfo Suarez maybe?
For the Germans:
Angela Merkel
For the Austrians:
Difficult to say.. so for now unknown
For Arabia:
King Faisal or King Salman
For Babylonia/Iraq:
Saddam Hussein
For Columbia:
Luis Carlos Galan?
For the Portuguese:
Also unknown right now
I can go on and on of course and these are just a few examples for modern leaderheads. I think for the British, America and French are fine in my opinion.
This isn't by the way to nitpick or some criticism but just a few sugesstions/opinions that I would like to see in the future. I wish I was a expert in modding otherwise I would have try to implement few of these myself and share it with you guys. For now I try to support this game by having these kinda suggestions or conversations by making this mod even better