Create portals between servers or an item to change server.
There are fantasy servers with 4 characters, I think it's better to create a portal and make a global server.
I know they will not do anything, but there I leave the idea just in case they read me.
Except that i dont see a point for this, to make this devs will need to rewrite game and wipe all characters, as such thing will need full change of database and how it works. So its impossible to make.