Maybe someone already pointed this out , but i didnt find any related link,topic to it.
In 500 map in general is huge issue 3 things.
1. morale of provinces - you can have just 1 capitol .. it will be super cool if you have an option to build some small capitol or smt. Lets say once you reach 200 cities (or more/less) you will be able to build additional capitol
2. planes - right now its not possible to flight from one corner to other corner with planes. Why there are no islands so you are able to fly with fighters. It will be much better if there would be that option. I know it would not be accurate to year 1914 but it will be much better and it will open much more option for a fight for example have additional option how to get to africa that would be super cool. Because right now when you are starting in America it sucks to get to other continents.
3. on later stage of the game maps are super slow. I have strong gaming PC but still to load the page it took few seconds and even sometimes it crash just because its not able to load the page or even better when you want to group units from bigger amount of cities thats almost imposible.