Personally i think 45 min is too long i now there is an rtd system but the majoraty of Players don't know about it and i have the feeling that noone actually knows how it works, so my suggestion is to reduce the time to 30 min per map. Perhaps you could test this for maby a weekend and ask the players what they think about it, additionally you could add a Map extension vote it the vote menu for the next map, so if all the Players think the map is great and fund to play you can choose vote for the map to become longer or the 4 new ones .