[2020] World Size

You can, in /Steam/steamapps/common/Eco/Eco_Data/Server/Configs/WorldGenerator.eco
"Dimensions": {
"x": 72,
"y": 72
},

Please note that when changing this you will need to start your server manually via the 64-Bit executable. The singleplayer server started from inside the game uses the 32 bit server and does not support bigger world sizes, it will crash on reaching the memory limit.

You can start it on the same computer, but you need to do so manually.

Well, you need to remove the old world before generating a new one.

The .db and .eco file in the Storage folder.

Originally posted by ossmpossm: what happened with "wetlands" were they ADDED in the new patch again?

Yes.

Originally posted by Sooner535{UFIP}: Can we have this as a server option by default rather than having to edit files?

No, as the 32-bit server that is used for singleplayer does not support increased world sizes.

No. If you don't have a public server, you don't need and should not change the world size to experience the game as intended.