Suggestion
Map list, when voting for a map, consists of and is restricted to the maps available on the server - even if the client doesn't have them.
I don't know how in-demand this feature is or even how practical this would be to do with the existing code but it should be feasible. It would require populating the map list with that from the server instead of the client.
There is potentially a problem for servers with a very large amount of maps if the list was obtained on connection but one possible solution would be to asynchronously request the list when the client chooses to vote for a map.
