The good thing: something like this would be pretty easy to do. I made this in less than an half an hour (would need a lot of polishing though). This picture could made to a dragdown chart like the map in GWX.
The bad thing: modding this in would demand a change to menu_1072_768.ini file which means trouble as most people already have changed menu_1072_768.ini files. Most people would need to add these kind of charts by editing the ini file themselves.