Loading time can take quite a while, especially for maps with more complex terrain. I think it would be better to have a maps folder in the install, so when a client connects to the server, if the client has the map, only the changes to the map need to be transferred. If the client doesn't have the map, it is downloaded, then the changes are transmitted.
This would make loading times during map changes very fast, because players would already have the map in their possession.
This system would slow down loading time initially, but once people build up their repository of typically used maps, the loading time should increase.
Obviously maps could be tagged for not undergoing through this process, especially classic gen or maps with copyright / agreements between map maker and server host.