As of now, i dont think there is a cvar associated with how many maps can display. RTV always does 5 maps. I will take a look at the un-compiled code and see if thats changeable.
Also, it randomly picks maps to display on RTV from a list of maps that i have selected (which i think are somewhere in this thread)
A new map rotation probably wont occur for a couple of more weeks when school starts back up and we reset stats/hold exec and CL votes/etc